I very much like the idea of a uniform algorithm for this - similarly to https://indieweb.org/post-type-discovery. During that session the list on https://spdx.org/licenses/ came up as a source for licence indication - unfortunately neither rel=“licence” nor microformats seem to be offering a way to indicate a machine readable licence indicator yet. It might be beneficial to include a proposition for that along with the algorithm.

Galtelli, the old capital of Sardinia has extremely narrow and quite steep streets, with adorable places to stay at; this is one of them.