Merge format documented?

Hello,

is the format that git normally uses for indicating merge conflicts in files (the <<< === >>> markers) documented somewhere? How exactly does it differ from the diff3 format (<<< ||| === >>>)? Diff3's -m mode seems to come close to what git does, except that git doesn't produce the ||| section:

	$ seq 1 7 > a
	$ seq 1 7 | sed -e 's/4/4b/' > b
	$ seq 1 7 | sed -e 's/3/3c/' > c
	$ diff3 -m c a b
	> 1
	> 2
	> <<<<<<< c
	> 3c
	> 4
	> ||||||| a
	> 3
	> 4
	> =======
	> 3
	> 4b
	> >>>>>>> b
	> 5
	> 6
	> 7

Git's output in this case is:

	> 1
	> 2
	> <<<<<<< this-branch
	> 3c
	> 4
	> =======
	> 3
	> 4b
	> >>>>>>> merged-branch
	> 5
	> 6
	> 7

Does git ever output a ||| section?

Thanks, Andreas