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Re: [DFDL-WG] Action 059: External specification of encoding, byte order
by Steve Hanson 12 Nov '09

12 Nov '09

As discussed on the call: For case 1) the DFDL xsd always wins, and the context is ignored. If the user wants to use the encoding/byte order from the context, then he must be explicit about this and use case 2) above Will adopt suggestion a). One question - are there any other DFDL properties like dfdl:encoding and dfdl:byteOrder that are commonly provided by context? How about dfdl:binaryFloatRepresentation, or dfdl:outputNewLine? Will not adopt suggestion b). Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 From: Steve Hanson/UK/IBM To: dfdl-wg(a)ogf.org Date: 05/11/2009 14:30 Subject: Action 059: External specification of encoding, byte order DFDL schemas can either: 1) specify fixed encoding(s)/byte order(s) for the data being described, 2) specify that the encoding/byte order is provided by the 'context' that invokes the DFDL processor (using the dfdl:defineVariable 'external' facility). ** For case 1), DFDL is faced with a problem. Namely what happens when the 'context' provides an encoding/byte order for the data, but the DFDL xsd specifies a different encoding/byte order. I think DFDL must make a statement about this situation, as there are several common scenarios where this could occur (HTTP, MIME, MQ). It is worth looking at the precedent set by XML in this regards. The analogous problem for XML is where the XML document itself specifies a different encoding (using the ?xml declaration) to the context. The recommendations for XML are stated in the appendix below - there is no universal rule. It is more complicated with DFDL though. A DFDL xsd can set up the encoding(s)/byte order(s) to use in several different places. Which of those would the context override? All of them? Just the one associated with the top-level structure? My conclusion is therefore that for case 1) the DFDL xsd always wins, and the context is ignored. If the user wants to use the encoding/byte order from the context, then he must be explicit about this and use case 2) above. There are two things that we could allow to be a bit more flexible: a) Pre-define $encoding and $byteOrder variables in the DFDL namespace. These would implictly have 'external' = 'true' and perhaps a 'defaultValue' as well. This simplifies the coding of a DFDL xsd for case 2). b) State that it is an implementation decision to provide an option to use a context encoding/byte order for case 1) instead of the ones in the DFDL xsd. In such a case, the context MUST override all encodings/byte orders in the system of xsds used by the DFDL processor. (In practice this is invariably a single encoding/byte order). . ** (Might be more than encoding & byte order - for example MQ also allows float format to be provided by context) Appendix: XML The equivalent situation for XML is where the XML document specifies its own encoding via the ?xml declaration, and the context also provides the encoding. There is no single rule, in summary: - Basicaly if there is a higher level protocol, then that defines the rules. - Eg, for MIME content-type text/xml, the context encoding is used. If this is omitted, the xml is assumed to be US-ASCII. The ?xml declaration encoding is not used. - Eg, for MIME content-type application/xml, the context encoding is used If this is omitted, the ?xml declaration encoding is used. - For files (where there is no context encoding) use of the ?xml declaration encoding is recommended. Note that in Message Broker, we always use the context encoding, as it should always be present. We never use the ?xml declaration. W3C XML 1.0 spec section F.2 Priorities in the Presence of External Encoding Information The second possible case occurs when the XML entity is accompanied by encoding information, as in some file systems and some network protocols. When multiple sources of information are available, their relative priority and the preferred method of handling conflict should be specified as part of the higher-level protocol used to deliver XML. In particular, please refer to [IETF RFC 3023] or its successor, which defines the text/xml and application/xml MIME types and provides some useful guidance. In the interests of interoperability, however, the following rule is recommended. If an XML entity is in a file, the Byte-Order Mark and encoding declaration are used (if present) to determine the character encoding. IETF RFC 3023 3.6 Summary The following list applies to text/xml, text/xml-external-parsed- entity, and XML-based media types under the top-level type "text" that define the charset parameter according to this specification: o Charset parameter is strongly recommended. o If the charset parameter is not specified, the default is "us- ascii". The default of "iso-8859-1" in HTTP is explicitly overridden. o No error handling provisions. o An encoding declaration, if present, is irrelevant, but when saving a received resource as a file, the correct encoding declaration SHOULD be inserted. The next list applies to application/xml, application/xml-external- parsed-entity, application/xml-dtd, and XML-based media types under top-level types other than "text" that define the charset parameter according to this specification: o Charset parameter is strongly recommended, and if present, it takes precedence. o If the charset parameter is omitted, conforming XML processors MUST follow the requirements in section 4.3.3 of [XML]. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Fw: DFDL: Default dfdl:format annotation
by Steve Hanson 11 Nov '09

11 Nov '09

As discussed on the WG call, it is clearer if the use of dfdl:defineXXXX is associated with a named re-usable annotation, and that a 'normal' unnamed DFDL annotation puts properties into use. With that in mind, when dfdl:format is used directly as an annotation on the xs:schema, it is putting properties into use. I therefore withdraw the proposal below. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 11/11/2009 17:48 ----- From: Steve Hanson/UK/IBM To: dfdl-wg(a)ogf.org Date: 11/11/2009 11:15 Subject: DFDL: Default dfdl:format annotation Alan and I were discussing this on Friday. We think that the 'default' dfdl:format would be better off contained within a dfdl:defineFormat annotation with no name, zero or one of which may exist in any given xsd. We think it makes things easier to document, specifically that dfdl:format now only appears in one place - as a child of dfdl:defineFormat, and that the term 'unnamed dfdl:defineFormat annotation' may be used to describe this annotation unambiguously. <dfdl:defineFormat> <dfdl:format ........ /> </dfdl:defineFormat> I'd like to add this to the first agenda item for today's call. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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DFDL: Default dfdl:format annotation
by Steve Hanson 11 Nov '09

11 Nov '09

Alan and I were discussing this on Friday. We think that the 'default' dfdl:format would be better off contained within a dfdl:defineFormat annotation with no name, zero or one of which may exist in any given xsd. We think it makes things easier to document, specifically that dfdl:format now only appears in one place - as a child of dfdl:defineFormat, and that the term 'unnamed dfdl:defineFormat annotation' may be used to describe this annotation unambiguously. <dfdl:defineFormat> <dfdl:format ........ /> </dfdl:defineFormat> I'd like to add this to the first agenda item for today's call. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Fw: Agenda for OGF DFDL WG call 11 November 2009 - 13:00 UK (8:00 ET)
by Steve Hanson 11 Nov '09

11 Nov '09

Agenda: Alan is on leave today so call will be run by Steve H 1. 051 Scoping Rules Review Suman's selectors examples 2. 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. Review Alan's updated spec fragment (see e-mail) 3. 059: External specification of encoding, byte order Review Steve H's proposal (see e-mail) 4. 045 Resolving points of uncertainty and parsing rules Continue discussion of semantics of discriminators and arrays Use web meeting to discuss Mike B's example (see e-mail) https://www2.gotomeeting.com/join/319038563 6. Test suite for DFDL Discuss Mike's e-mail and what IBM is doing as part of its implementation work 5. Go through remaining actions 6. Plan to finish DFDL v1 Updated strawman schedule Activity Schedule Who Resolve Action items - 23 Nov 2009 WG Write up work items 16 Nov - 4 Dec 2009 AP Restructure and complete specification 23 Nov - 4 Dec 2009 AP WG review 7 Dec - 18 Dec 2009 WG Incorporate review comments 4 Jan - 29 Jan 2010 AP + OGF Editor Review / Incorporate changes 1 Feb - 1 Mar 2010 OGF OGF Public Comment period (60 days) 1 Mar - 30 Apr 2010 OGF OGF 28 Munich 15-19 March 2010 Current Actions: No Action 012 AP/SH: Update decimalCalendarScheme 10/9: Not allocated yet 17/9: No update 24/9: Add calendar binary formats to actions 22/10: No progress 16/1: proposal distributed and discussed. Will be redistributed 21/1: add locale, 04/02: changed from locale to specific properties 18/2: Need more investigation of ICU strict/lax behaviour. 08/04: Not discussed 22/04: AP to complete asap once the ICU strict/lax behaviour is understood. 29/04: No progress 06/05: No progress 13/05: Calendar has been added to latest spec version v034 but still a few details to clarify. 20/05: No Progress 27/05: No Progress 03/06: No Progress (low priority) 09/06: No Progress (low priority) 17/06: SH to check ICU code for lax calendar behaviour 24/06: no progress 01/07: no progress 15/07: no progress 29/07: no progress 05/08: no progress 12/08: no progress 19/08: Inconsistencies are being found in ICU behaviour so Calendars need reviewing again. 26/08: Specific three character short time zones may not be maintained during round tripping when there is more than one short form for a time zone offset. Because dates and datetimes in the infoset only maintain a time zone offset so on unparsing it isn't possible to say which short form will be selected for a particular offset when there is more than one possible. Need to document. 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 28/10: Discussed ICU farctional seconds behaviour. SF to send latest understanding. 04/11: no progress 11/11: 033 MB: Need for scope indicator on discriminator 08/04: In progress within IBM 22/04: Waiting for TK to return from leave to complete. 29/04: TK has sent examples shown need for discriminators beyond choice. Agreed. MB to respond to TK 06/05: Discussed suggestion of adding type indicator to discriminator. MB to provide examples. 15/03: Semantic documented in v034. MB to provide examples of need for scope indicator on discriminator 20/05: MB to provide examples of need for scope indicator on discriminator (but lower priority than action 029) 27/05: No Progress (lower priority) .... 19/08: No Progress (lower priority) 26/08: No Progress (lower priority) 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: no progress 28/10: no progress 04/11: Mike to produce examples for choices with variable occurrence arrays. 11/11: 037 All: Approach for XML Schema 1.0 UPA checks. 22/04: Several non-XML models, when expressed in their most obvious DFDL Schema form, would fail XML Schema 1.0 Unique Particle Attribution checks that police model ambiguity. And even re-jigging the model sometimes fails to fix this. Note this is equally applicable to XMl Schema 1.1 and 1.0. While the DFDL parser/unparser can happily resolve the ambiguities, the issue is one of definition. If an XSD editor that implements UPA checks is used to create DFDL Schema, then errors will be flagged. DFDL may have to adopt the position that: a)DFDL parser/unparser will not implement some/all UPA checks (exact checks tbd) b) XML Schema editors that implement UPA checks will not be suitable for all DFDL models c) If DFDL annotations are removed, the resulting pure XSD will not always be valid (ie, the equivalent XML is ambiguous and can't be modelled by XML Schema 1.0) Ongoing in case another solution can be found. 29/04: Will ask DG and S Gao for opinion before closing 06/05: Discussed S Gao email and suggestions. Decided need to review all XML UPA rules and decide which apply to dfdl. 20/05: SH or SKK to investigate 27/05: No Progress 03/06: The concern is that some dfdl schemas will fail UPA check when validation is turned on or when editted using tooling that enforces UPA checks. Renaming fields will resolve some/most issues. Need documentation that describes issue and best practice. 17/06: no change 24/06: no change 01/07: no prgress 15/07: No Progress (lower priority) 29/07: No Progress (lower priority) 05/08: No Progress (lower priority) 12/08: No Progress (lower priority) 19/08: Clarify that this action is to go through the XML UPA checks to assess impact on dfdl schemas and advice best practice. Name clashes is just one example. SH or SKK 26/08: No Progress (lower priority) 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 04/11: no progress 11/11: 045 20/05 AP: Speculative Parsing 27/05: Psuedo code has been circulated. Review for next call 03/06: Comments received and will be incorporated 09/06: Progress but not discussed 17/06: Discussed briefly 24/06: No Progress 01/07: No Progress 15/07: No progress. MB not happy with the way the algorithm is documented, need to find a better way. 29/07: No Progress 05/08: No Progress. Will document behaviour as a set of rules. 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 16/09: no progress 30/09: AP distributed proposal and others commented. Brief discussion AP to incorporate update and reissue 07/10: Updated proposal was discussed.Comments will be incorporated into the next version. 14/10: Alan to update proposal to include array scenario where minOccurs > 0 21/10: Updated proposal reviewed 28/10: Updated proposal reviewed see minutes 04/11: Discussed semantics of disciminators on arrays. MB to produce examples 11/11: 049 20/05 AP Built-in specification description and schemas 03/06: not discussed 24/06: No Progress 24/06: No Progress (hope to get these from test cases) 15/07: No progress. Once available, the examples in the spec should use the dfdl:defineFormat annotations they provide. ..... 19/08: No Progress (lower priority) 26/08: No Progress (lower priority) 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Discussed the real need for this being in the specification. It seemed that the main value is it define a schema location for downloading 'known' defaults from the web. 28/10: no progress 04/11: no progress 11/11: 051 Scoping rules. MB: to document change to scoping rules to satisfy implementation concerns 17/06: MB and SH proposals discussed. Needs further discussion 24/06: AP to update presentation with latest proosal 24/06: AP had updated presentation. MB to review 08/07: Discussed at length. Simple types will now take annotations. Variables will be used for parameters. 15/07: No further progress. Needs final write up. 29/07: No Progress 05/08: No Progress 12/08: No Progress 19/08: AP will document new syntax rules. 26/08: No Progress 09/09: AP has documented new scoping rules. Not discussed 16/09: Not disussed. AP to update element reference examples 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 04/11: defineFormat can only contain one active format block, Drop baseFormat, SKK to produce examples for selectors. 04/11: Further discussion see minutes. SKK to produce examples of selectors. 11/11: 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 04/11: MB to look at lengthUints = bits 11/11: 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 28/10: no progress 04/11: no progress 11/11: 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 28/10: no progress 04/11: no progress 11/11: 062 SH investigate technical writer support. 28/10: SH had contacted S Gao to understand the W3 process and support. 04/11: no progress 11/11: 063 Write DFDL primer and test cases. 11/11: Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Fw: Scoping : dfdl:defineFormat
by Steve Hanson 11 Nov '09

11 Nov '09

For discussion on today's WG call - see agenda. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 ----- Forwarded by Steve Hanson/UK/IBM on 11/11/2009 10:53 ----- From: Steve Hanson/UK/IBM To: Suman Kalia/Toronto/IBM@IBMCA Cc: Alan Powell/UK/IBM@IBMGB, Mike Beckerle <mbeckerle.dfdl(a)gmail.com> Date: 05/11/2009 11:46 Subject: Re: Scoping : dfdl:defineFormat Hi Suman - you have correctly captured the behaviour in both X and Y cases. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 From: Suman Kalia/Toronto/IBM@IBMCA To: Alan Powell/UK/IBM@IBMGB, Mike Beckerle <mbeckerle.dfdl(a)gmail.com>, Steve Hanson/UK/IBM@IBMGB Date: 05/11/2009 04:21 Subject: Scoping : dfdl:defineFormat Reference discussion this morning, attached is an example that captures scoping rule for dfdl:format based on my understanding.. Please send your comments / corrections etc .. <?xml version="1.0" encoding="UTF-8"?>  <dfdl:defineFormat name="fmtX" xmlns:dfdl="http://www.ogf.org/dfdl/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ogf.org/dfdl/ DFDL_v1_035.xsd "> <dfdl:format encoding="ascii" lengthUnits="characters" /> <dfdl:format selector="selA" encoding="ebcdic" lengthUnits="bits" /> <dfdl:format selector="selB" encoding="ebcdic-custom" lengthUnits="bytes" /> </dfdl:defineFormat> <dfdl:defineFormat name="fmtZX" xmlns:dfdl="http://www.ogf.org/dfdl/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ogf.org/dfdl/ DFDL_v1_035.xsd "> <dfdl:format ref="fmtX" lengthUnits="bytes" />   <dfdl:format ref="fmtX" selector="selA" lengthUnits="bytes" />   <dfdl:format ref="fmtX" selector="selB" lengthUnits="bytes" />   </dfdl:defineFormat>  <dfdl:defineFormat name="fmtY" xmlns:dfdl="http://www.ogf.org/dfdl/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ogf.org/dfdl/ DFDL_v1_035.xsd "> <dfdl:format encoding="ascii" lengthUnits="characters" /> </dfdl:defineFormat> <dfdl:defineFormat name="fmtZY" xmlns:dfdl="http://www.ogf.org/dfdl/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ogf.org/dfdl/ DFDL_v1_035.xsd "> <dfdl:format ref="fmtY" lengthUnits="bytes" />   <dfdl:format ref="fmtY" selector="selA" lengthUnits="bytes" />   <dfdl:format ref="fmtY" selector="selB" lengthUnits="bytes" />   </dfdl:defineFormat> Suman Kalia IBM Toronto Lab WMB Toolkit Architect and Development Lead WebSphere Business Integration Application Connectivity Tools http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.h… Tel : 905-413-3923 T/L 969-3923 Fax : 905-413-4850 T/L 969-4850 Internet ID : kalia(a)ca.ibm.com Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Action 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase.
by Alan Powell 10 Nov '09

10 Nov '09

Attached is the updates for Action 061 I have also clarified more clearly when the properties apply and improved some of the descriptions Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Minutes for OGF DFDL Working Group Call, Nov-04-2009
by Alan Powell 05 Nov '09

05 Nov '09

Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, Nov-04-2009 Attendees Mike Beckerle (Oco) Suman Kalia (IBM) Steve Hanson (IBM) Alan Powell (IBM) Steve Marting (Progeny) Stephanie Fetzer(IBM) Apologies Peter Lambros (IBM) 1. 051 Scoping Rules Continued discussion on draft v7. After last weeks decision to disallow multiple dfdl:format at the same annotation point, Steve pointed out that dfdl:defineFormat was now inconsistent in that it allowed multiple dfdl:formats. Decided that dfdl:defineFormat will only allow one dfdl:format annoation. We then discussed whether it was still necessary to have the dfdl:defineFornat baseFormat property and ref property its only dfdl:format annotation. Having 2 properties allows multiple inheritance but that is inconsistent other places where dfdl:format is used. We noted that the dfdl:format ref property allowed re-factoring more easily than the baseFormat property. Decided that the baseFormat property is no longer needed and will be removed. There was a long discussion on the semantics of selectors on the dfdl:format annoations in a dfdl:defineFormat block. Agreed that the current definition that selectors apply independently at each annotation point but added that dfdl:defineFormat is an annotation point equivalent to annotation points on schema components. Suman agreed to produce some examples to show the semantics of selectors. 2. Resolving points of uncertainty and parsing rules Discussed the semantics of discriminators on variable length arrays. Went through many examples of behaviours with no firm conclusion that a complete description found. Concluded that the best way forward was to produce a complete set of use cases. Mike B agreed to do this as part of action 033. 4. Go through remaining actions Actions updated below 5. Plan to finish DFDL v1 We agreed that the target should be to have the DFDL V1 specification ready for public review by OGF 28 in March 2010. Alan will redo the schedule and try to get more details of the OGF process. Mike suggested that to make the spec useful we also needed a primer and a good set of worked examples that could be used as implementation 'test cases' - Action item raised. It was noted that the examples in the spec should mainly be to clarify points of semantics and not to explain simple use cases. We also discussed then need to reorganize the spec to make it more readable, It was felt that it was more important to complete the spec that reorganize it. Alan and Steve H will look at the structure to see how much needs to be done. Next call 11 November 13:00 UK Meeting closed, 15:10 Next action: 064 Actions raised at this meeting No Action 063 Write DFDL primer and test cases. Current Actions: No Action 012 AP/SH: Update decimalCalendarScheme 10/9: Not allocated yet 17/9: No update 24/9: Add calendar binary formats to actions 22/10: No progress 16/1: proposal distributed and discussed. Will be redistributed 21/1: add locale, 04/02: changed from locale to specific properties 18/2: Need more investigation of ICU strict/lax behaviour. 08/04: Not discussed 22/04: AP to complete asap once the ICU strict/lax behaviour is understood. 29/04: No progress 06/05: No progress 13/05: Calendar has been added to latest spec version v034 but still a few details to clarify. 20/05: No Progress 27/05: No Progress 03/06: No Progress (low priority) 09/06: No Progress (low priority) 17/06: SH to check ICU code for lax calendar behaviour 24/06: no progress 01/07: no progress 15/07: no progress 29/07: no progress 05/08: no progress 12/08: no progress 19/08: Inconsistencies are being found in ICU behaviour so Calendars need reviewing again. 26/08: Specific three character short time zones may not be maintained during round tripping when there is more than one short form for a time zone offset. Because dates and datetimes in the infoset only maintain a time zone offset so on unparsing it isn't possible to say which short form will be selected for a particular offset when there is more than one possible. Need to document. 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 28/10: Discussed ICU farctional seconds behaviour. SF to send latest understanding. 04/11: no progress 033 MB: Need for scope indicator on discriminator 08/04: In progress within IBM 22/04: Waiting for TK to return from leave to complete. 29/04: TK has sent examples shown need for discriminators beyond choice. Agreed. MB to respond to TK 06/05: Discussed suggestion of adding type indicator to discriminator. MB to provide examples. 15/03: Semantic documented in v034. MB to provide examples of need for scope indicator on discriminator 20/05: MB to provide examples of need for scope indicator on discriminator (but lower priority than action 029) 27/05: No Progress (lower priority) .... 19/08: No Progress (lower priority) 26/08: No Progress (lower priority) 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: no progress 28/10: no progress 04/11: Mike to produce examples for choices with variable occurrence arrays. 037 All: Approach for XML Schema 1.0 UPA checks. 22/04: Several non-XML models, when expressed in their most obvious DFDL Schema form, would fail XML Schema 1.0 Unique Particle Attribution checks that police model ambiguity. And even re-jigging the model sometimes fails to fix this. Note this is equally applicable to XMl Schema 1.1 and 1.0. While the DFDL parser/unparser can happily resolve the ambiguities, the issue is one of definition. If an XSD editor that implements UPA checks is used to create DFDL Schema, then errors will be flagged. DFDL may have to adopt the position that: a)DFDL parser/unparser will not implement some/all UPA checks (exact checks tbd) b) XML Schema editors that implement UPA checks will not be suitable for all DFDL models c) If DFDL annotations are removed, the resulting pure XSD will not always be valid (ie, the equivalent XML is ambiguous and can't be modelled by XML Schema 1.0) Ongoing in case another solution can be found. 29/04: Will ask DG and S Gao for opinion before closing 06/05: Discussed S Gao email and suggestions. Decided need to review all XML UPA rules and decide which apply to dfdl. 20/05: SH or SKK to investigate 27/05: No Progress 03/06: The concern is that some dfdl schemas will fail UPA check when validation is turned on or when editted using tooling that enforces UPA checks. Renaming fields will resolve some/most issues. Need documentation that describes issue and best practice. 17/06: no change 24/06: no change 01/07: no prgress 15/07: No Progress (lower priority) 29/07: No Progress (lower priority) 05/08: No Progress (lower priority) 12/08: No Progress (lower priority) 19/08: Clarify that this action is to go through the XML UPA checks to assess impact on dfdl schemas and advice best practice. Name clashes is just one example. SH or SKK 26/08: No Progress (lower priority) 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 04/11: no progress 045 20/05 AP: Speculative Parsing 27/05: Psuedo code has been circulated. Review for next call 03/06: Comments received and will be incorporated 09/06: Progress but not discussed 17/06: Discussed briefly 24/06: No Progress 01/07: No Progress 15/07: No progress. MB not happy with the way the algorithm is documented, need to find a better way. 29/07: No Progress 05/08: No Progress. Will document behaviour as a set of rules. 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 16/09: no progress 30/09: AP distributed proposal and others commented. Brief discussion AP to incorporate update and reissue 07/10: Updated proposal was discussed.Comments will be incorporated into the next version. 14/10: Alan to update proposal to include array scenario where minOccurs > 0 21/10: Updated proposal reviewed 28/10: Updated proposal reviewed see minutes 04/11: Discussed semantics of disciminators on arrays. MB to produce examples 049 20/05 AP Built-in specification description and schemas 03/06: not discussed 24/06: No Progress 24/06: No Progress (hope to get these from test cases) 15/07: No progress. Once available, the examples in the spec should use the dfdl:defineFormat annotations they provide. ..... 19/08: No Progress (lower priority) 26/08: No Progress (lower priority) 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Discussed the real need for this being in the specification. It seemed that the main value is it define a schema location for downloading 'known' defaults from the web. 28/10: no progress 04/11: no progress 051 Scoping rules. MB: to document change to scoping rules to satisfy implementation concerns 17/06: MB and SH proposals discussed. Needs further discussion 24/06: AP to update presentation with latest proosal 24/06: AP had updated presentation. MB to review 08/07: Discussed at length. Simple types will now take annotations. Variables will be used for parameters. 15/07: No further progress. Needs final write up. 29/07: No Progress 05/08: No Progress 12/08: No Progress 19/08: AP will document new syntax rules. 26/08: No Progress 09/09: AP has documented new scoping rules. Not discussed 16/09: Not disussed. AP to update element reference examples 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 04/11: defineFormat can only contain one active format block, Drop baseFormat, SKK to produce examples for selectors. 04/11: Further discussion see minutes. SKK to produce examples of selectors. 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 04/11: MB to look at lengthUints = bits 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 28/10: no progress 04/11: no progress 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 28/10: no progress 04/11: no progress 062 SH investigate technical writer support. 28/10: SH had contacted S Gao to understand the W3 process and support. 04/11: no progress 063 Write DFDL primer and test cases. Closed actions: Work items: No Item target version status 005 Improvements on property descriptions not started 011 How speculative parsing works (combining choice and variable-occurence - currently these are separate) (from action 045) awaiting completion of actions 045 012 Reordering the properties discussion: move representation earlier, improve flow of topics not started 033 Numeric data - what physical reps are allowed for what logical types (from action 020) 037 ensure all behaviour documented 036 Update dfdl schema with change properties ongoing 038 Improve length section including bit handling some improvement in 036 042 Mapping of the DFDL infoset to XDM none not required for V1 specification 051 Revised scoping rules (from action 051) 037 awaiting completion of action 051 058 textPadCharacter %#rxx limitation and split to textxxxxPadCharacter 037 059 limit terminatorCanBeMissing to last element in schema. Ignore elsewhere. 037 060 New empty string semantic for dfdl:binaryBooleanTrueRep 037 061 Change maxOccurs violations from processing error to validation error (if not 'fixed') 037 062 Drop calendarUseZForUTC. describe zU, IU and TU symbols 037 063 DefineFormat can contain only one active format. Drop baseFormat 037 ã Copyright IBM Corp. 1998, 2007 All Rights Reserved Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Action 059: External specification of encoding, byte order
by Steve Hanson 05 Nov '09

05 Nov '09

DFDL schemas can either: 1) specify fixed encoding(s)/byte order(s) for the data being described, 2) specify that the encoding/byte order is provided by the 'context' that invokes the DFDL processor (using the dfdl:defineVariable 'external' facility). ** For case 1), DFDL is faced with a problem. Namely what happens when the 'context' provides an encoding/byte order for the data, but the DFDL xsd specifies a different encoding/byte order. I think DFDL must make a statement about this situation, as there are several common scenarios where this could occur (HTTP, MIME, MQ). It is worth looking at the precedent set by XML in this regards. The analogous problem for XML is where the XML document itself specifies a different encoding (using the ?xml declaration) to the context. The recommendations for XML are stated in the appendix below - there is no universal rule. It is more complicated with DFDL though. A DFDL xsd can set up the encoding(s)/byte order(s) to use in several different places. Which of those would the context override? All of them? Just the one associated with the top-level structure? My conclusion is therefore that for case 1) the DFDL xsd always wins, and the context is ignored. If the user wants to use the encoding/byte order from the context, then he must be explicit about this and use case 2) above. There are two things that we could allow to be a bit more flexible: a) Pre-define $encoding and $byteOrder variables in the DFDL namespace. These would implictly have 'external' = 'true' and perhaps a 'defaultValue' as well. This simplifies the coding of a DFDL xsd for case 2). b) State that it is an implementation decision to provide an option to use a context encoding/byte order for case 1) instead of the ones in the DFDL xsd. In such a case, the context MUST override all encodings/byte orders in the system of xsds used by the DFDL processor. (In practice this is invariably a single encoding/byte order). . ** (Might be more than encoding & byte order - for example MQ also allows float format to be provided by context) Appendix: XML The equivalent situation for XML is where the XML document specifies its own encoding via the ?xml declaration, and the context also provides the encoding. There is no single rule, in summary: - Basicaly if there is a higher level protocol, then that defines the rules. - Eg, for MIME content-type text/xml, the context encoding is used. If this is omitted, the xml is assumed to be US-ASCII. The ?xml declaration encoding is not used. - Eg, for MIME content-type application/xml, the context encoding is used If this is omitted, the ?xml declaration encoding is used. - For files (where there is no context encoding) use of the ?xml declaration encoding is recommended. Note that in Message Broker, we always use the context encoding, as it should always be present. We never use the ?xml declaration. W3C XML 1.0 spec section F.2 Priorities in the Presence of External Encoding Information The second possible case occurs when the XML entity is accompanied by encoding information, as in some file systems and some network protocols. When multiple sources of information are available, their relative priority and the preferred method of handling conflict should be specified as part of the higher-level protocol used to deliver XML. In particular, please refer to [IETF RFC 3023] or its successor, which defines the text/xml and application/xml MIME types and provides some useful guidance. In the interests of interoperability, however, the following rule is recommended. If an XML entity is in a file, the Byte-Order Mark and encoding declaration are used (if present) to determine the character encoding. IETF RFC 3023 3.6 Summary The following list applies to text/xml, text/xml-external-parsed- entity, and XML-based media types under the top-level type "text" that define the charset parameter according to this specification: o Charset parameter is strongly recommended. o If the charset parameter is not specified, the default is "us- ascii". The default of "iso-8859-1" in HTTP is explicitly overridden. o No error handling provisions. o An encoding declaration, if present, is irrelevant, but when saving a received resource as a file, the correct encoding declaration SHOULD be inserted. The next list applies to application/xml, application/xml-external- parsed-entity, application/xml-dtd, and XML-based media types under top-level types other than "text" that define the charset parameter according to this specification: o Charset parameter is strongly recommended, and if present, it takes precedence. o If the charset parameter is omitted, conforming XML processors MUST follow the requirements in section 4.3.3 of [XML]. Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Agenda for OGF DFDL WG call 21 Octobert 2009 - 13:00 UK (8:00 ET)
by Alan Powell 04 Nov '09

04 Nov '09

1. 051 Scoping Rules Check latest draft v7. Confirm agreement to "It is a schema definition error if more that one format annotation occurs at the same annotation point, except when selectors are used, or if the same property is defined in long and short form." 2. 045 Resolving points of uncertainty and parsing rules Confirm wording for 'potentially point of uncertainty" Confirm parsing rule 1. The length of a dfdl:representation 'text' component which has a terminator, separator or parent terminator or separator does not match the required length. 3. Go through remaining actions 4. Plan to finish DFDL v1 Status 10 Actions ( issues to be resolved ) 10 Work items (features to be documented, areas to be improved) Strawman Schedule Activity Schedule Who Resolve Action items 23 Oct - 30 Oct 2009 WG Write up work items 23 Oct - 2 Nov 2009 AP Restructure and complete specification 23 Oct - 13 Nov 2009 AP WG review 16 Nov - 27 Nov 2009 WG Incorporate review comments 30 Nov - 7 Dec 2009 AP OGF Editor Review 7 Dec - 19 Dec 2009 OGF OGF Public Comment period (60 days) 4 Jan - 5 Mar 2010 OGF OGF 28 Munich 15-19 March 2010 Current Actions: No Action 012 AP/SH: Update decimalCalendarScheme 10/9: Not allocated yet 17/9: No update 24/9: Add calendar binary formats to actions 22/10: No progress 16/1: proposal distributed and discussed. Will be redistributed 21/1: add locale, 04/02: changed from locale to specific properties 18/2: Need more investigation of ICU strict/lax behaviour. 08/04: Not discussed 22/04: AP to complete asap once the ICU strict/lax behaviour is understood. 29/04: No progress 06/05: No progress 13/05: Calendar has been added to latest spec version v034 but still a few details to clarify. 20/05: No Progress 27/05: No Progress 03/06: No Progress (low priority) 09/06: No Progress (low priority) 17/06: SH to check ICU code for lax calendar behaviour 24/06: no progress 01/07: no progress 15/07: no progress 29/07: no progress 05/08: no progress 12/08: no progress 19/08: Inconsistencies are being found in ICU behaviour so Calendars need reviewing again. 26/08: Specific three character short time zones may not be maintained during round tripping when there is more than one short form for a time zone offset. Because dates and datetimes in the infoset only maintain a time zone offset so on unparsing it isn't possible to say which short form will be selected for a particular offset when there is more than one possible. Need to document. 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Will produce a list of known issues. 28/10: Discussed ICU farctional seconds behaviour. SF to send latest understanding. 033 MB: Need for scope indicator on discriminator 08/04: In progress within IBM 22/04: Waiting for TK to return from leave to complete. 29/04: TK has sent examples shown need for discriminators beyond choice. Agreed. MB to respond to TK 06/05: Discussed suggestion of adding type indicator to discriminator. MB to provide examples. 15/03: Semantic documented in v034. MB to provide examples of need for scope indicator on discriminator 20/05: MB to provide examples of need for scope indicator on discriminator (but lower priority than action 029) 27/05: No Progress (lower priority) .... 19/08: No Progress (lower priority) 26/08: No Progress (lower priority) 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: Action re-titled and assigned to Mike B 21/10: no progress 28/10: no progress 037 All: Approach for XML Schema 1.0 UPA checks. 22/04: Several non-XML models, when expressed in their most obvious DFDL Schema form, would fail XML Schema 1.0 Unique Particle Attribution checks that police model ambiguity. And even re-jigging the model sometimes fails to fix this. Note this is equally applicable to XMl Schema 1.1 and 1.0. While the DFDL parser/unparser can happily resolve the ambiguities, the issue is one of definition. If an XSD editor that implements UPA checks is used to create DFDL Schema, then errors will be flagged. DFDL may have to adopt the position that: a)DFDL parser/unparser will not implement some/all UPA checks (exact checks tbd) b) XML Schema editors that implement UPA checks will not be suitable for all DFDL models c) If DFDL annotations are removed, the resulting pure XSD will not always be valid (ie, the equivalent XML is ambiguous and can't be modelled by XML Schema 1.0) Ongoing in case another solution can be found. 29/04: Will ask DG and S Gao for opinion before closing 06/05: Discussed S Gao email and suggestions. Decided need to review all XML UPA rules and decide which apply to dfdl. 20/05: SH or SKK to investigate 27/05: No Progress 03/06: The concern is that some dfdl schemas will fail UPA check when validation is turned on or when editted using tooling that enforces UPA checks. Renaming fields will resolve some/most issues. Need documentation that describes issue and best practice. 17/06: no change 24/06: no change 01/07: no prgress 15/07: No Progress (lower priority) 29/07: No Progress (lower priority) 05/08: No Progress (lower priority) 12/08: No Progress (lower priority) 19/08: Clarify that this action is to go through the XML UPA checks to assess impact on dfdl schemas and advice best practice. Name clashes is just one example. SH or SKK 26/08: No Progress (lower priority) 09/09: no progress 16/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 045 20/05 AP: Speculative Parsing 27/05: Psuedo code has been circulated. Review for next call 03/06: Comments received and will be incorporated 09/06: Progress but not discussed 17/06: Discussed briefly 24/06: No Progress 01/07: No Progress 15/07: No progress. MB not happy with the way the algorithm is documented, need to find a better way. 29/07: No Progress 05/08: No Progress. Will document behaviour as a set of rules. 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 16/09: no progress 30/09: AP distributed proposal and others commented. Brief discussion AP to incorporate update and reissue 07/10: Updated proposal was discussed.Comments will be incorporated into the next version. 14/10: Alan to update proposal to include array scenario where minOccurs > 0 21/10: Updated proposal reviewed 28/10: Updated proposal reviewed see minutes 049 20/05 AP Built-in specification description and schemas 03/06: not discussed 24/06: No Progress 24/06: No Progress (hope to get these from test cases) 15/07: No progress. Once available, the examples in the spec should use the dfdl:defineFormat annotations they provide. ..... 19/08: No Progress (lower priority) 26/08: No Progress (lower priority) 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: Discussed the real need for this being in the specification. It seemed that the main value is it define a schema location for downloading 'known' defaults from the web. 28/10: no progress 051 Scoping rules. MB: to document change to scoping rules to satisfy implementation concerns 17/06: MB and SH proposals discussed. Needs further discussion 24/06: AP to update presentation with latest proosal 24/06: AP had updated presentation. MB to review 08/07: Discussed at length. Simple types will now take annotations. Variables will be used for parameters. 15/07: No further progress. Needs final write up. 29/07: No Progress 05/08: No Progress 12/08: No Progress 19/08: AP will document new syntax rules. 26/08: No Progress 09/09: AP has documented new scoping rules. Not discussed 16/09: Not disussed. AP to update element reference examples 30/09: Significant dissatisfaction with proposed new rules. New proposal developed during call. AP to document. 07/10: New proposal was refined. Details in minutes. 14/10: Discussed at length. Details in minutes. 21/10: Discussed at length. Details in minutes. 056 resolve lenghtUnit=bits including fillbytes 12/08: No Progress 19/08: No Progress 26/08: No Progress 09/09: no progress 30/09: no progress 07/10: no progress 14/10: no progress 21/10: no progress 28/10: no progress 059 9/9: define how encoding, byteorder and floating point format externally 16/09: no progress 07/10: no progress 14/10: no progress 21/10: SH to investigate 28/10: no progress 061 Refactor dfdl:textNumberFormat to remove dfdl:numberBase. 14/10: Base 2, 8, 16 numbers are invariably integers without formatting, use of pattern etc is overkill 21/10: no progress 28/10: no progress 062 SH investigate technical writer support. 28/10: SH had contacted S Gao to understand the W3 process and support. Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Re: [DFDL-WG] DFDL scoping v7
by Alan Powell 29 Oct '09

29 Oct '09

Steve Fixed. Thanks Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 From: Steve Hanson/UK/IBM To: Alan Powell/UK/IBM@IBMGB Cc: dfdl-wg(a)ogf.org, dfdl-wg-bounces(a)ogf.org Date: 28/10/2009 17:05 Subject: Re: [DFDL-WG] DFDL scoping v7 Alan, some comments: 1) Fig 2 <xs:annotation> <xs:appinfo source=?http://www.ogf.org/dfdl/?> <dfdl:defineFormat name='myFormat' encoding="ASCII" /> </xs:appinfo> </xs:annotation> I don't think the spec allows the encoding property directly on the dfdl:defineFormat ? There needs to be a dfdl:format. 2) Glossary defines "directly relevant" but should be defining "applicable". Regards Steve Hanson Programming Model Architect, WebSphere Message Brokers, OGF DFDL WG Co-Chair, Hursley, UK, Internet: smh(a)uk.ibm.com, Phone (+44)/(0) 1962-815848 From: Alan Powell/UK/IBM@IBMGB To: dfdl-wg(a)ogf.org Date: 28/10/2009 13:05 Subject: [DFDL-WG] DFDL scoping v7 Sent by: dfdl-wg-bounces(a)ogf.org For todays call Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell(a)uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU [attachment "ogf-dfdl-new-scoping-rules-with-default-V7.doc" deleted by Steve Hanson/UK/IBM] -- dfdl-wg mailing list dfdl-wg(a)ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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