When hg is invoked without parameters, the short list help is displayed. When hg is executed without parameters ( or hg is executed with the 'help shortlist' command ) the short help list is displayed. If the 'help' command is passed on the commandline the full help list is displayed. In both the cases if the switch '-v' is passed, the help contains also the aliases of the short/full commands list and the global switches.

+ hg init
+ hg add a
+ hg commit -m first -d 0 0 a
+ hg add sub/b
+ hg commit -m second -d 0 0 sub/b
321
+ hg co 0
cat: sub/b: No such file or directory
ls: sub: No such file or directory