I think tl;dr differs from a summary in that it is written as a response to hostility coming from someone who thinks the post is verbose. When I have seen it u

I think tl;dr differs from a summary in that it is written as a response to hostility coming from someone who thinks the post is verbose. When I have seen it used, it has consistently been more terse and to the point than summaries generally are. It may seem awkward and inaccessible to those unfamiliar with it, but I do think it is a specific enough form of a summary to warrant its own term.