diff --git a/base/include/hidl/HidlInternal.h b/base/include/hidl/HidlInternal.h
index 6c0d8df..9b9457f 100644
--- a/base/include/hidl/HidlInternal.h
+++ b/base/include/hidl/HidlInternal.h
@@ -28,6 +28,18 @@
 namespace hardware {
 namespace details {
 
+// tag for pure interfaces (e.x. IFoo)
+struct i_tag {};
+
+// tag for server interfaces (e.x. BnHwFoo)
+struct bnhw_tag {};
+
+// tag for proxy interfaces (e.x. BpHwFoo)
+struct bphw_tag {};
+
+// tag for server interfaces (e.x. BsFoo)
+struct bs_tag {};
+
 //Templated classes can use the below method
 //to avoid creating dependencies on liblog.
 void logAlwaysFatal(const char *message);