diff --git a/doc/README.dissector b/doc/README.dissector
index 6df380078e..7538abecfc 100644
--- a/doc/README.dissector
+++ b/doc/README.dissector
@@ -133,6 +133,10 @@ FIELDDISPLAY    --For FT_UINT{8,16,24,32,64} and FT_INT{8,16,24,32,64):
                   otherwise:
                     (must be) BASE_NONE
 
+                --For FT_STRING, FT_STRINGZ and FT_UINT_STRING:
+
+                  STR_ASCII or STR_UNICODE
+
                 --For all other types:
 
                   BASE_NONE