X means any state and U means an unmerged index.
-
-Author
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-Written by Junio C Hamano <gitster@pobox.com> and Linus Torvalds <torvalds@osdl.org>
-
-Documentation
---------------
-Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
-
GIT
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Part of the linkgit:git[1] suite