# Check Current Branch
$ hg branch
default

# Create New Branch
$ hg branch new-branch
marked working directory as branch new-branch

# Confirm New Branch
$ hg branch
new-branch

# List Branches (Several Weeks Later)
$ hg branches
new-branch                     200:ad96a97024ce
default                        100:019016980509 (inactive)

# Switch Back to Default
$ hg update -C default

# Confirm Switch
$ hg branch
default

$ hg branches
new-branch                     200:ad96a97024ce
default                        100:019016980509 (inactive)

$ hg branch
new-branch

$ hg update -C default
10 files updated, 0 files merged, 5 files removed, 0 files unresolved
(branch merge, don't forget to commit)

$ hg merge new-branch

$ hg commit -m "merged new-branch back into default"

$ hg branch
default

$ hg merge --usage
hg merge: option --usage not recognized
hg merge [-f] [[-r] REV]

merge working directory with another revision

	Merge the contents of the current working directory and the
	requested revision. Files that changed between either parent are
	marked as changed for the next commit and a commit must be
	performed before any further updates are allowed.

	If no revision is specified, the working directory's parent is a
	head revision, and the repository contains exactly one other head,
	the other head is merged with by default.  Otherwise, an explicit
	revision to merge with must be provided.

options:

 -f --force  force a merge with outstanding changes
 -r --rev    revision to merge