Grammar: should be "URL to fetch" or "URL to be fetched". I suggest "resource to fetch, as URI".

Please show examples of valid ``remote`` URIs, including which schemes are are allowed (``git``, ``ssh``, ``https``, ``http``, ``ftp``, ``rsync``, ``file``, and pure path, as spec'd in the git-fetch docs).

Is authentication available for private git repos on GitHub? Will this work for local git repositories, or only GitHub? Is there a way to specify branch and tag requests on the git repo? If so, please show examples of these. Does this clone the entire repo? Or does it do something like ``git archive``? 

*(I don't think this needs to go in the docs, but what is the effect of using that clone in a union file system for future layers? Does the whole repo get copied to each layer after future ``git fetch``es, or just the diffs? This could affect how much storage is used.)*

Please show examples of a range of valid `t` tags, including any techniques needed to escape html entities for use in the URI.