diff --git a/src/meshTools/searchableSurface/searchableSurfaceCollection.H b/src/meshTools/searchableSurface/searchableSurfaceCollection.H
index 2004bf9400c24c01a7bf2a1c475973f05a1c6562..dd4c5fdce215c5ccf3743a97541f9075114c668e 100644
--- a/src/meshTools/searchableSurface/searchableSurfaceCollection.H
+++ b/src/meshTools/searchableSurface/searchableSurfaceCollection.H
@@ -26,7 +26,8 @@ Class
     Foam::searchableSurfaceCollection
 
 Description
-    Union of transformed searchableSurfaces
+    Set of transformed searchableSurfaces. Does not do boolean operations.
+    So when meshing might find parts 'inside'.
 
 SourceFiles
     searchableSurfaceCollection.C