--long always use long format
--abbrev[=<n>] use <n> digits to display SHA-1s
---------------------------------------------
++
+Note that some subcommand (e.g. `git grep`) may behave differently
+when there are things on the command line other than `-h`, but `git
+subcmd -h` without anything else on the command line is meant to
+consistently give the usage.
--help-all::
Some Git commands take options that are only used for plumbing or that