SHA1::
Synonym for object name.
+shallow repository::
+ A shallow repository has an incomplete history some of
+ whose commits have parents cauterized away (in other
+ words, git is told to pretend that these commits do not
+ have the parents, even though they are recorded in the
+ commit object). This is sometimes useful when you are
+ interested only in the recent history of a project even
+ though the real history recorded in the upstream is
+ much larger. A shallow repository is created by giving
+ `--depth` option to gitlink:git-clone[1], and its
+ history can be later deepened with gitlink:git-fetch[1].
+
symref::
Symbolic reference: instead of containing the SHA1 id itself, it
is of the format 'ref: refs/some/thing' and when referenced, it