Defaults to HEAD.
<format>::
- A string that interpolates `%(fieldname)` from the object
- pointed at by a ref being shown. The format is the same as
+ A string that interpolates `%(fieldname)` from a tag ref being shown
+ and the object it points at. The format is the same as
that of linkgit:git-for-each-ref[1]. When unspecified,
defaults to `%(refname:strip=2)`.