Usually link-only answers are considered low quality and their author is encouraged to edit them to include the relevant part of the linked page in the answer itself and if they don't do so, their answer can get deleted.
But some link-only answers answer the question, but link to something that can't be copied. For example, this question asks for how to translate localized error messages from Microsoft into English, and the accepted answer is a link-only answer, but the link points to a search service from Microsoft to search for the translation:
Microsoft provides the Terminology Search in his Language Portal, it can be found here: https://www.microsoft.com/Language/en-US/Search.aspx
If the link would have been to something that could be copied, I would have flagged this and posted a comment from here to ask the user to include the information in their answer. But this answer links to search page, so the information can't be copied to the answer (on Stack Overflow you could use a snippet to copy the code from the search page, but that wouldn't be much different from just linking to the search page, and besides Super User doesn't even have snippets). So the answer is useful, answers the question, and I don't really see how it could be improved.
I see two ways to deal with it: Either treat it as a normal link-only answer, but then valuable information would be lost, or leave it alone, but according to the FAQ link-only answers are considered low quality and should be flagged.
This isn't the only such link-only answer that I've seen, I've also seen a few link-only answers with links to download pages, and the installation programs can of course not be copied to an answer.
So are link-only answers of that kind acceptable? What should I do next time I see an answer like that in a review queue?