Bundle
hg bundle [-f] [-a] [-r REV]... [--base REV]... FILE [DEST]
Generates a compressed changegroup file collecting changesets not found in the other repository.
There is some consensus to use the file extension "*.hg" for bundle files.
Help text: http://www.selenic.com/mercurial/hg.1.html#bundle
See also: CreateBundleOfAllChanges, LookingIntoBundles