Here's the description for this property from the spec, including a change for errata 2.100. I am concerned about the red sentence about length units.
textOutputMinLength Non-negative Integer.  

Only used when dfdl:textPadKind is 'padChar' and dfdl:lengthKind is 'delimited', 'prefixed', 'pattern' or 'endOfParent' or 'explicit' and dfdl:length is an expression, and type is not xs:string

Specifies the minimum representation length during unparsing for simple types that do not allow the xs:minlength facet to be specified. The units are specified by the dfdl:lengthUnits property.
If dfdl:textOutputMinLength is zero or less than the length of the representation text then no padding occurs.

Annotation: dfdl:element, dfdl:simpleType



However, when parsing, dfdl:lengthUnits is only used for a 'specified length' so that's dfdl:lengthKind 'explicit', 'implicit' and 'prefixed'. When 'delimited', 'pattern' or 'endOfParent' dfdl:lengthUnits is not used. I think we should be saying:

"For dfdl:lengthKind 'delimited', 'pattern' and 'endOfParent' the length units are characters. For other dfdl:lengthKinds the length units are specified by the dfdl:lengthUnits property."


Same argument applies to XSD minLength facet for xs:strings.

Regards

Steve Hanson
Architect, Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
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