Re: [PATCH 2/3] format-patch: teach `--header-cmd`

>> +--[no-]header-cmd=<cmd>::
>> +	Run _<cmd>_ for each patch. _<cmd>_ should output valid RFC 2822
>> +	email headers. This can also be configured with
>> +	the configuration variable `format.headerCmd`. Can be turned off
>> +	with `--no-header-cmd`. This works independently of
>> +	`--[no-]add-header`.
>> ++
>> +_<cmd>_ has access to these environment variables:
>> ++
>> +	GIT_FP_HEADER_CMD_VERSION
>
> Better use a nested description list like this:
>
> GIT_FP_HEADER_CMD_VERSION;;
>   The version of this API. Currently `1`. _<cmd>_ may return exit code
>   `2` in order to signal that it does not support the given version.
>

>> ++
>> +The version of this API. Currently `1`. _<cmd>_ may return exit code
>> +`2` in order to signal that it does not support the given version.
>> ++
>> +	GIT_FP_HEADER_CMD_HASH
>> ++
>> +The hash of the commit corresponding to the current patch. Not set if
>> +the current patch is the cover letter.
>> ++
>> +	GIT_FP_HEADER_CMD_COUNT
>> ++
>> +The current patch count. Increments for each patch.
>> ++
>> +`git format-patch` will error out if _<cmd>_ returns a non-zero exit
>> +code.
>> +
>>  --[no-]cover-letter::
>>  	In addition to the patches, generate a cover letter file
>>  	containing the branch description, shortlog and the overall diffstat.  You can
>
>
> Overall, thank you for correctly marking up placeholders and options.