diff --git a/broadcastradio/1.1/default/VirtualProgram.h b/broadcastradio/1.1/default/VirtualProgram.h
index 33ec292..a14830d 100644
--- a/broadcastradio/1.1/default/VirtualProgram.h
+++ b/broadcastradio/1.1/default/VirtualProgram.h
@@ -25,6 +25,12 @@
 namespace V1_1 {
 namespace implementation {
 
+/**
+ * A radio program mock.
+ *
+ * This represents broadcast waves flying over the air,
+ * not an entry for a captured station in the radio tuner memory.
+ */
 struct VirtualProgram {
     ProgramSelector selector;