In the middle block 'Contribute' in page https://lang.moodle.org/?lang=el we can see a phrase like this:
Many thanks to #1, #2, #3 and #4 for their recent contributions!
where e.g. #1 is a name of a recent contributor.
Commas are ok but the word 'and' is not translated in any language and is always 'and'.
I can not find it in language strings so I suspect it is hardcoded in AMOS pages.