[3.0] b2bad5a Explicitly document that concatenation is only supported for the builtins.

[Tollef Fog Heen]

commit b2bad5a679f91a07d0240f20a284cc03d9511eca
Author: Andreas Plesner Jacobsen <apj at mutt.dk>
Date:   Thu Nov 10 22:49:57 2011 +0100

    Explicitly document that concatenation is only supported for the builtins.
    
    Fixes #1042

diff --git a/doc/sphinx/reference/vcl.rst b/doc/sphinx/reference/vcl.rst
index aaca549..3aeb001 100644
--- a/doc/sphinx/reference/vcl.rst
+++ b/doc/sphinx/reference/vcl.rst
@@ -634,8 +634,11 @@ default code.
 
 Multiple subroutines
 ~~~~~~~~~~~~~~~~~~~~
-If multiple subroutines with the same name are defined, they are
-concatenated in the order in which the appear in the source.
+If multiple subroutines with the the name of one of the builtin
+ones are defined, they are concatenated in the order in which they
+appear in the source.
+The default versions distributed with Varnish will be implicitly
+concatenated as a last resort at the end.
 
 Example:::
 
@@ -661,8 +664,6 @@ Example:::
 	  }
 	}
 
-The builtin default subroutines are implicitly appended in this way.
-
 Variables
 ~~~~~~~~~