One sub-category that I would argue for immediate removal involves questions where advice has been given (but not accepted) on providing additional context for example.

If the person who asked the question has been "seen" on the site (as per their profile) since the comments were posted but has not responded, then we can reasonably infer that the additional information is not available; and hence that the question can not be salvaged.

http://genealogy.stackexchange.com/q/1916 is an example of this type (but by no means the only one).

One sub-category that I would argue for immediate removal involves questions where advice has been given (but not accepted) on providing additional context for example.

If the person who asked the question has been "seen" on the site (as per their profile) since the comments were posted but has not responded, then we can reasonably infer that the additional information is not available; and hence that the question can not be salvaged.

https://genealogy.stackexchange.com/q/1916 is an example of this type (but by no means the only one).