Each patch is a changeset against the base tree plus the preceding patches.
All patches are listed, in order, in the file ./series. You manage the
-series file.
+series file. Lines in the series file which start with `#' are ignored.
Any currently-applied patches are described in the file
./applied-patches. The patch scripts manage this file.
cat pc/$(toppatch).pc
+join-patch patchname
+
+ "joins" the named patch to the current topmost patch.
+
+ Use this when you want to merge two patches into one. All the
+ files which `patchname' affects are added to pc/$(toppatch).pc (if
+ they are not already there) and patch `patchname' is applied. The
+ top patch remains unchanged. You'll need to run refpatch afterwards.
+
mpatch
A low-level thing to generate patches