diff --git a/src/finiteVolume/fields/fvPatchFields/derived/directMappedFixedValue/directMappedFixedValueFvPatchField.H b/src/finiteVolume/fields/fvPatchFields/derived/directMappedFixedValue/directMappedFixedValueFvPatchField.H
index e672c07e9269d7035cf82f0b68c0cde939d09465..8d6038913ed91c94241e90f1ca7e6818dc223cf0 100644
--- a/src/finiteVolume/fields/fvPatchFields/derived/directMappedFixedValue/directMappedFixedValueFvPatchField.H
+++ b/src/finiteVolume/fields/fvPatchFields/derived/directMappedFixedValue/directMappedFixedValueFvPatchField.H
@@ -25,7 +25,13 @@ Class
     Foam::directMappedFixedValueFvPatchField
 
 Description
-    Recycles the value at a set of internal faces back to *this.
+    Recycles the value at a set of cells or patch faces back to *this. Can not
+    sample internal faces (since volField not defined on faces).
+
+    mode = NEARESTCELL : sample nearest cell
+    mode = NEARESTPATCHFACE : sample nearest face on selected patch
+    mode = NEARESTFACE : sample nearest face on any patch. Note: does not
+                         warn if nearest actually is on internal face!
 
 SourceFiles
     directMappedFixedValueFvPatchField.C
diff --git a/src/finiteVolume/fields/fvPatchFields/derived/directMappedVelocityFluxFixedValue/directMappedVelocityFluxFixedValueFvPatchField.H b/src/finiteVolume/fields/fvPatchFields/derived/directMappedVelocityFluxFixedValue/directMappedVelocityFluxFixedValueFvPatchField.H
index 95f3954a1ad3b00aad6c13c079ffefa59c3e7ecb..3aecda00c0d4b054ad916cba4d285c7858030052 100644
--- a/src/finiteVolume/fields/fvPatchFields/derived/directMappedVelocityFluxFixedValue/directMappedVelocityFluxFixedValueFvPatchField.H
+++ b/src/finiteVolume/fields/fvPatchFields/derived/directMappedVelocityFluxFixedValue/directMappedVelocityFluxFixedValueFvPatchField.H
@@ -27,6 +27,11 @@ Class
 Description
     Recycles the velocity and flux at a patch to this patch
 
+    mode = NEARESTCELL : sample nearest cell
+    mode = NEARESTPATCHFACE : sample nearest face on selected patch
+    mode = NEARESTFACE : sample nearest face on any patch. Note: does not
+                         warn if nearest actually is on internal face!
+
 SourceFiles
     directMappedVelocityFluxFixedValueFvPatchField.C
 
diff --git a/src/meshTools/directMapped/directMappedPolyPatch/directMappedPatchBase.H b/src/meshTools/directMapped/directMappedPolyPatch/directMappedPatchBase.H
index 9d3fd3a6229fa3cd1f63653a5e1b105fec81d62f..577f014dee7c54016aace419511fe32e7d413497 100644
--- a/src/meshTools/directMapped/directMappedPolyPatch/directMappedPatchBase.H
+++ b/src/meshTools/directMapped/directMappedPolyPatch/directMappedPatchBase.H
@@ -66,9 +66,9 @@ public:
         //- Mesh items to sample
         enum sampleMode
         {
-            NEARESTCELL,
-            NEARESTPATCHFACE,
-            NEARESTFACE
+            NEARESTCELL,        // nearest cell
+            NEARESTPATCHFACE,   // faces on selected patch
+            NEARESTFACE         // nearest face
         };
 
 private:
@@ -201,7 +201,7 @@ public:
             return sampleRegion_;
         }
 
-        //- Patch (only if NEARESTBOUNDARY)
+        //- Patch (only if NEARESTPATCHFACE)
         const word& samplePatch() const
         {
             return samplePatch_;