Patch Set 1:

remote HEAD:
search for set-hard in http://www.kernel.org/pub/software/scm/git/docs/git-remote.html

According to that section a remote HEAD specifies the default branch for the named remote. If you leave out the branch in a remote ref the default branch is assumed. E.g. "if the default branch for origin is set to master, then origin may be specified wherever you would normally specify origin/master"