Explain when tip branches get merged into mainline.
    
Signed-off-by: Christian Kujau <lists@nerdbynature.de>
Suggested-by: Borislav Petkov <bp@alien8.de>

---
diff --git a/Documentation/process/maintainer-tip.rst b/Documentation/process/maintainer-tip.rst
index 572a3289c9cb..d43cc2272e83 100644
--- a/Documentation/process/maintainer-tip.rst
+++ b/Documentation/process/maintainer-tip.rst
@@ -421,6 +421,9 @@ allowing themselves a breath. Please respect that.
 The release candidate -rc1 is the starting point for new patches to be
 applied which are targeted for the next merge window.
 
+So called _urgent_ branches will be merged into mainline during the
+stabilization phase of each release.
+
 
 Git
 ^^^

-- 
BOFH excuse #282:

High altitude condensation from U.S.A.F prototype aircraft has contaminated the primary subnet mask. Turn off your computer for 9 days to avoid damaging it.