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 b
+ hg commit -m commit #0 -d 0 0
+ hg commit -mcomment #1 -d 0 0
+ hg update 0
+ hg commit -A -mcomment #2 -d 0 0
removing b
+ hg update 1
this update spans a branch affecting the following files:
 b
aborting update spanning branches!
(use update -m to merge across branches or -C to lose changes)