diff --git a/src/cas/os/vxWorks/README b/src/cas/os/vxWorks/README
index 47ee432df..024556cac 100644
--- a/src/cas/os/vxWorks/README
+++ b/src/cas/os/vxWorks/README
@@ -2,6 +2,7 @@
 WORK IN PROGRESS
 
 this directory contains the vxWorks os dependent source for 
-the EPICS ca server
+the EPICS ca server. This is a multi-threaded port of the
+server.