Your opinion: "sr_Latn" or "sr@Latn"

[buhtz]

Hello,
I am interested in your opinion.

Serbian in latin script: Would you choose "sr_Latn" or "sr@Latn"?

Weblate ofers "sr_Latn" but not "sr@Latn".

But the Debian folks (using GNU gettext) telling me I should use "sr@Latn". I am not able to find an official list or standard for such language code suffixes.

Some more background:
Upstream project: https://github.com/bit-team/backintime
Weblate instance: https://translate.codeberg.org/engage/backintime/
Discussion at debian-i18n: https://lists.debian.org/debian-i18n/2025/03/msg00000.html
Debian package: https://tracker.debian.org/pkg/backintime
The gettext error message: https://i18n.debian.org/l10n-pkg-status/b/backintime.html

Regards,
Christian