Basically when blocking a user with something like "{{blocktemplate}} [[Article]]", and then looking at [[Special:CentralAuth/Username]] on a different wiki, the links in the block log point to local targets rather than pointing to the wiki the block was issued on.
This can be seen at https://www.wikidata.org/w/index.php?title=Special%3ACentralAuth&target=Legosock where I blocked my alt. account on testwiki.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=45629