@Takot Thanks for the report. We've had issues with the same string on Android, mainly because the purpose of the string is complicated and we're not adequately explaining what we're using it for.

I'm going to write a patch which improves the description for the string. I'd appreciate your feedback on whether this improvement is helpful to you when translating it.

Change 190941 had a related patch set uploaded (by Deskana):
Improve descriptions for some strings in Share a Fact feature.

https://gerrit.wikimedia.org/r/190941

Patch-For-Review

Change 190941 merged by Mhurd:
Improve descriptions for some strings in Share a Fact feature.

https://gerrit.wikimedia.org/r/190941

In T89604#1042406, @Deskana wrote:

@Takot @Nemo_bis Please do reopen this ticket if what I've done isn't enough and more clarification/input from me is needed. Thanks!

Thanks for the explanation, but I'm not sure that helps. What Takot reported is that this is a weird case of word order restriction: the l10n is ok, but the grammatically correct word order ("@Wikipedia" as first word) is not suitable for the target system.

Docs should probably suggest something like «Replace "@Wikipedia" with "#Wikipedia" if it comes first in your translation», or you could use a translatable hashtag in the message and then have the software append "@Wikipedia" at the bottom (Amazon does something like this, they let you type something but they add some parts of the tweet on their own).