conflict markers on recursive strategy with diff3 enabled

Hi!

I'm sitting down hunting for conflict examples and while looking through past conflicts in git I found one that has a format that I hadn't seen before. When merging the parents of 8b79343fc0 we get this:

<<<<<<< HEAD

/*
* Unlink the .pack and associated extension files.
* Does not unlink if 'force_delete' is false and the pack-file is
* marked as ".keep".
*/
extern void unlink_pack_path(const char *pack_name, int force_delete);
||||||| merged common ancestors

=======

That is with merge.conflictStyle set to diff3. What I would like to know is if the details about how the additional information that is not normally seen on a conflict has to be interpreted (to be read as "the part about the temporary branches"). I see some explanation about it in [1] but when checking inside "git help merge" all I see is that when you are using diff3 you will get the content of the parent but there's more stuff than just that. Is it documented somewhere?

Thanks!

[1]https://stackoverflow.com/questions/31392513/git-diff3-conflict-style-temporary-merge-branch