A revision parameter typically, but not necessarily, names a
commit object. They use what is called an 'extended SHA1'
+syntax. Here are various ways to spell object names. The
+ones listed near the end of this list are to name trees and
+blobs contained in a commit.
* The full SHA1 object name (40-byte hexadecimal string), or
a substring of such that is unique within the repository.
name the same commit object if there are no other object in
your repository whose object name starts with dae86e.
+* An output from `git-describe`; i.e. a closest tag, followed by a
+ dash, a 'g', and an abbreviated object name.
* A symbolic ref name. E.g. 'master' typically means the commit
object referenced by $GIT_DIR/refs/heads/master. If you
happen to have both heads/master and tags/master, you can
and dereference the tag recursively until a non-tag object is
+* A suffix ':' followed by a path; this names the blob or tree
+ at the given path in the tree-ish object named by the part
+* A colon, optionally followed by a stage number (0 to 3) and a
+ colon, followed by a path; this names a blob object in the
+ index at the given path. Missing stage number (and the colon
+ that follows it) names an stage 0 entry.
Here is an illustration, by Jon Loeliger. Both node B and C are
a commit parents of commit node A. Parent commits are ordered