++
+When used in `git-push`, the <src> side can be an
+arbitrary "SHA1 expression" that can be used as an
+argument to `git-cat-file -t`. E.g. `master~4` (push
+four parents before the current master head).
++
+For `git-push`, the local ref that matches <src> is used
+to fast forward the remote ref that matches <dst>. If
+the optional plus `+` is used, the remote ref is updated
+even if it does not result in a fast forward update.
++
+For `git-fetch` and `git-pull`, the remote ref that matches <src>
+is fetched, and if <dst> is not empty string, the local
+ref that matches it is fast forwarded using <src>.
+Again, if the optional plus `+` is used, the local ref
+is updated even if it does not result in a fast forward
+update.
++
+[NOTE]
+If the remote branch from which you want to pull is
+modified in non-linear ways such as being rewound and
+rebased frequently, then a pull will attempt a merge with
+an older version of itself, likely conflict, and fail.
+It is under these conditions that you would want to use
+the `+` sign to indicate non-fast-forward updates will
+be needed. There is currently no easy way to determine
+or declare that a branch will be made available in a
+repository with this behavior; the pulling user simply
+must know this is the expected usage pattern for a branch.
++
+[NOTE]
+You never do your own development on branches that appear
+on the right hand side of a <refspec> colon on `Pull:` lines;
+they are to be updated by `git-fetch`. If you intend to do
+development derived from a remote branch `B`, have a `Pull:`
+line to track it (i.e. `Pull: B:remote-B`), and have a separate
+branch `my-B` to do your development on top of it. The latter
+is created by `git branch my-B remote-B` (or its equivalent `git
+checkout -b my-B remote-B`). Run `git fetch` to keep track of
+the progress of the remote side, and when you see something new
+on the remote branch, merge it into your development branch with
+`git pull . remote-B`, while you are on `my-B` branch.
+The common `Pull: master:origin` mapping of a remote `master`
+branch to a local `origin` branch, which is then merged to a
+local development branch, again typically named `master`, is made
+when you run `git clone` for you to follow this pattern.
++
+[NOTE]
+There is a difference between listing multiple <refspec>
+directly on `git-pull` command line and having multiple
+`Pull:` <refspec> lines for a <repository> and running
+`git-pull` command without any explicit <refspec> parameters.
+<refspec> listed explicitly on the command line are always
+merged into the current branch after fetching. In other words,
+if you list more than one remote refs, you would be making
+an Octopus. While `git-pull` run without any explicit <refspec>
+parameter takes default <refspec>s from `Pull:` lines, it
+merges only the first <refspec> found into the current branch,
+after fetching all the remote refs. This is because making an
+Octopus from remote refs is rarely done, while keeping track
+of multiple remote heads in one-go by fetching more than one
+is often useful.
++
+Some short-cut notations are also supported.
++
+* `tag <tag>` means the same as `refs/tags/<tag>:refs/tags/<tag>`;
+ used with pull or fetch, it requests fetching everything up to
+ the given tag.
+* A parameter <ref> without a colon is equivalent to
+ <ref>: when pulling/fetching, and <ref>`:`<ref> when
+ pushing. That is, do not store it locally if
+ fetching, and update the same name if pushing.