Check also theese messages and their documentations:
In T127609#2050204, @Liuxinyu970226 wrote:This message is a part of #MediaWiki-Extensions-SemanticMediaWiki, therefore please use https://github.com/SemanticMediaWiki/SemanticMediaWiki/issues to report, thank you very much.
In T126908#2026572, @Aklapper wrote:"Message definition (Echo)" hence setting Echo / Notifications (Echo) project. For future reference, please try to set the correct project. Thanks!
In T122259#1900877, @Aklapper wrote:@Macofe: I do not see any "i18n issue" here. If you think there is a "i18n issue", please explain why and how this affects i18n. Currently I only see a potential typo.
Same with 'item' in Wikimedia:Pageviews-select2-max-items/en
Thanks Nemo, Nike and Raymond.
In T128338#2071030, @Nemo_bis wrote:I double-checked and indeed, as far as I can see, all the old translations of this message are still in place: