I have just been presented with an answer in the VLQ queue that consisted essentially in a link to a preprint on arXiv. The user having posted it is a high reputation user, so he definitely knows the rules about link-only answers. Furthermore, he was also the one who had asked the question, and the author of the preprint. He is a serious mathematician, and the preprint is obviously of high level (I cannot judge its correctness, though). This put me in an uncomfortable position, and I recommended the deletion of his post, but only half-heartedly. Which leads me to ask:
should we relax the requirement about link-only posts, and accept links to arXiv, HAL and possibly other repositories that the MO community considers stable (i.e. they offer stable URLs that are not susceptible of change)?
If so, we shall need some sort of poll in order for us to vote on the list of such repositories.
(I, for one, am in favour of my own proposal :) but I would like to hear the opinion of the community.)