Originally posted at translatewiki.net [1] but no reply there so I'm lifting it here instead.
There is insufficient information about what an "alert" is in this context and how it differs from "messages" and "notifications"? Without this information accurate translations are difficult.
[1] https://translatewiki.net/wiki/Thread:Support/About_MediaWiki:Echo-notification-alert/sv
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=71585