Rework package categories and add Debian sources unchanged but recompiled.

maintainers/PackagingGuide.md

@@ -44,19 +44,22 @@ issue against the relevant devuan/`<source_package>` with the title
 
 ## Package Categories
 
-There are four categories of packages in Devuan:-
+There are five categories of packages in Devuan:-
 
- 1. Devuan only, not present in Debian.
+ 1. Used directly from Debian unchanged without recompilation.
  2. Forked from Debian and modified.
- 3. Present in Debian but Devuan is the packaging upstream (currently only
-    elogind).
- 4. Used directly from Debian unchanged.
 
-In general, packages in category 2 are forked so they work on Devuan with
+The vast majority of packages fall within these first two categories.  In
+general, packages in category 2 are forked so they work on Devuan with
 non-systemd init systems.
 
-Packages in the last category will usually not be present in Devuan's git or
-jenkins. However, packages can change category over time and so remnants of
+ 3. Present in Debian but Devuan is the packaging upstream (currently only
+    elogind).
+ 4. Debian source used unmodified but recompiled on Devuan.
+ 5. Devuan only, not present in Debian.
+
+Packages in categories 1, 4 and 5 will not usually be present in Devuan's git
+repository. However, packages can change category over time and so remnants of
 previous incarnations may remain.
 
 ## Package Forking Policy