OK, but the ISO-11179 Standard doesn't seem to actually say that. Here's a purported copy of Part 5 -- Naming and identification principles -- of the standard (as linked to from the aforementioned MSDN forum thread:
https://www.ftb.ca.gov/aboutFTB/Projects/ITSP/Part_5_Naming_...
The word "collective" doesn't show up in the document.
The word "plural" shows up twice, both times in item #a of "Lexical rules":
> a) Nouns are used in singular form only. Verbs (if any) are in the present tense.
> NOTE In Japanese, this rule shall not be applied because of no plural form of nouns and no distinction of verb tense.
The only reference on Wikipedia to the ISO 11179 standard making that recommendation has since been deleted for being unsubstantiated:
https://en.wikipedia.org/w/index.php?title=Data_element_name...
edit: The apparently inaccurate content is talked about on the "Data element name" Talk page: https://en.wikipedia.org/wiki/Talk:Data_element_name