backout: make help more explicit about what backout does The help for backout explains: The backout command merges the reverse effect of the reverted changeset into the working directory. Unfortunately, that does not make it obvious to a newcomer what the backout command does. Since it performs a 3-way merge, what is the common ancestor? Will the result be automatically committed? What is this reverted changeset --- is it the rev passed with -r on the command line or its inverse? So try to clarify the description, avoiding jargon and being explicit about what happens from the user's perspective. Thanks to Gilles Moris, Steve Borho, Kevin Bullock, and timeless for help.