I came across a format today which allows fields to be fixed length or delimited on a per element basis. The delimiter is allowed to vary on a per element basis. This indicates that the delimiter would be naturally modelled as a terminator in DFDL, as opposed to a separator. However, the final terminator in the document must never appear. Not can be missing, but must be missing. This suggests that dfdl:documentFinalTerminatorCanBeMissing is not flexible enough, and needs to apply on unparsing, and maybe needs to be a 3 way property... - 'yes' -> can be omitted when parsing, output when unparsing - 'no' -> must be present when parsing, output when unparsing -, 'always'. -> must not be present when parsing, must not be output when unparsing Regards Steve Hanson Architect, Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh@uk.ibm.com tel:+44-1962-815848 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