'update'::
-Fetch updates for a named set of remotes in the repository as defined by
-remotes.<group>. If a named group is not specified on the command line,
+Fetch updates for remotes or remote groups in the repository as defined by
+remotes.<group>. If neither group nor remote is specified on the command line,
the configuration parameter remotes.default will be used; if
remotes.default is not defined, all remotes which do not have the
configuration parameter remote.<name>.skipDefaultUpdate set to true will