Template:User Greek nationality is part of WikiProject Userboxes. This means that the WikiProject has identified it as part of the userboxes system. WikiProject Userboxes itself is an attempt to improve, grow, and standardize Wikipedia's articles and templates related to the userbox system, used on many users' pages. We need all your help, so join in today!UserboxesWikipedia:WikiProject UserboxesTemplate:WikiProject UserboxesUserboxes articles
This template is within the scope of WikiProject Greece, a collaborative effort to improve the coverage of Greece on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.GreeceWikipedia:WikiProject GreeceTemplate:WikiProject GreeceGreek articles
Section-Text Copied from here:
The Greek nationality template had been coded in, as I at least grasp it, a wrong way.
The setting of category was being done outside the userbox template.
I.e. as understand it, users were hence not being added to
this group-category.
Moreover some users (including me) had copied-used this text-code
{{User Greek nationality}}
instead of this one
{{Template:User Greek nationality}}
to their page.
I don't know if this caused them to be listed here (I hadn't been) but since I've now changed the template's code, the people listed here have become much fewer.
So people if you want to belong to this category add the text to your pages in its entirety(see above).
I think this will do the trick though I'm not sure it is indeed needed.
If you think or I know I'm wrong etc (in example in how the code works) please comment etc.