I have noticed that we get questions related to 500 errors and the White Screen of Death.
I think we need a tag for both of these so people can locate questions easier, and that we should potentially make the tags synonyms (since a WSOD is nearly always a 500 error).
I went ahead and added wsod to a few questions, and stubbed out the tag wiki.
There really isn't a consensus on the SE sites about what tag to use for 500 errors. SO uses "http-status-code-500", and SF uses "500-error". Personally, I think the SO one is better, and it does autocomplete if you start typing "500".
I also think we should make an effort to edit questions to add wsod as appropriate.