The lowercase form of should occurs 10 times, 8 of which seem to be possible SHOULD as follows:
In addition, within this Specification, the keyword “CONDITIONAL” should be interpreted as potentially “REQUIRED” or “OPTIONAL” depending on the surrounding context. (I have commented elsewhere on this provision.)
3.2.2 Selecting values from lists
An existing vetted list should be referenced for defaults, but users could also reference their own value list .
3.2.3 EDXL Extensions
Note that this mechanism should be used only for required elements – if an element is optional, it could be completely replaced by any community extension, with its own name and structure.
4 Data Dictionary (normative)
Acronyms that are part of a type/element identifier should preserve their all upper case format.
Where possible, an existing vetted list should be offered as defaults, but allow users to extend values on that list, or to use their own value list
4.11 Patient Age
Regarding units/unitsDefault: unitsDefault is a default units list that should be used if possible. If a different list needs to be used or the default list needs to be extended, units should be used.
This is a custom list of age units that should be used only when necessary.