In addition to the previously reported strings in T84004 (many of them already resolved)...

Thanks for reviewing it, @Bastien Montagne (mont29)
I saw that other task, before creating this one, but I thought as these strings were not really disambiguation requests, would better fit in their own task, facing 2.92 release.

While translating the new strings for 2.81 I've found that the string "Parents" (used for "main" particles) is now also wrongly used for one of the new "Affect Only" options (Origins/Locations/Parents) of the transform tools toolbar.
Please, that should remain as a separate string.

es and es_ES are identical, I propose we remove es_ES

Hi @Aaron Carlisle (Blendify) ,
I'm the translator of the UI into Spanish (one of the few languages that has been consistently maintained throughout these years), I've handed it alone since 2011, and a couple of times people tried to jump onboard to help, but unfortunately they ultimately never did any significant contribution, for different reasons I think.
I understand what you are looking for with these changes, and it could be a good thing, if done properly.

@Bastien Montagne (mont29)
I've found the "Cycles" string used for the render engine name is still used as the name of the Cycles F-Modifier, displayed in the UI when you add one of those.