Good morning. As discussed yesterday, here is a fresh version with improvements and corrections applied. I added a note to the Discussion section, reproduced here for convenience. --- Yesterday's conference expressed the view that the version 3 model contained more detail than was useful. Version 4 removes some of the new abstractions to bring it closer to version 2, but retains most of the relationships. The new naming conventions (Global*, *Reference, *Definition) didn't find favour, and this version uses established names for abstractions discussed in the XML Schema specification. Other changes correct errors and misunderstandings: only simple types may have explicit base types; DFDL doesn't support All groups or explicit Group constructs in groups; some associations were incorrectly described as aggregations. Dfdl annotations can be used at any annotation point. There are some restrictions, but this model cannot show details clearly so they are left for a different form of presentation or for later addition. --- Regards, Simon Simon Parker Software Consultant PolarLake 80 Harcourt Street Dublin 2, Ireland Phone +353 1 449-1075 Fax +353 1 449-1011 Web http://www.polarlake.com/ The information transmitted in this email is intended for the addressee only and may contain confidential and/or privileged material. Any review, retransmission, dissemination, reliance upon or other use of this information by persons or entities other than the addressee is prohibited. If you think, for any reason, that this message may have been addressed to you in error, we would ask you to notify the sender immediately by return email and delete the material. PolarLake Limited | Registered in Dublin, Ireland | Number 357324 | Registered office as above.