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If the client has requested a positive depth, the server will compute
-the set of commits which are no deeper than the desired depth, starting
-at the client's wants. The server writes 'shallow' lines for each
+the set of commits which are no deeper than the desired depth. The set
+of commits start at the client's wants.
+
+The server writes 'shallow' lines for each
commit whose parents will not be sent as a result. The server writes
an 'unshallow' line for each commit which the client has indicated is
shallow, but is no longer shallow at the currently requested depth