diff --git a/src/finiteVolume/finiteVolume/ddtSchemes/CrankNicolsonDdtScheme/CrankNicolsonDdtScheme.H b/src/finiteVolume/finiteVolume/ddtSchemes/CrankNicolsonDdtScheme/CrankNicolsonDdtScheme.H
index 5c505047b9..1568890ded 100644
--- a/src/finiteVolume/finiteVolume/ddtSchemes/CrankNicolsonDdtScheme/CrankNicolsonDdtScheme.H
+++ b/src/finiteVolume/finiteVolume/ddtSchemes/CrankNicolsonDdtScheme/CrankNicolsonDdtScheme.H
@@ -56,6 +56,13 @@ Description
     interFoam family of solvers.  Boundedness cannot be guaranteed with the
     backward scheme.
 
+Note
+    The Crank-Nicolson coefficient for the implicit part of the RHS is related
+    to the off-centering coefficient by
+    \verbatim
+        cnCoeff = 1.0/(1.0 + ocCoeff);
+    \endverbatim
+
 See Also
     Foam::Euler
     Foam::backward