Tweaks to previous, DNS label charset commit.
diff --git a/src/dns-protocol.h b/src/dns-protocol.h
index 7f5d686..4b71746 100644
--- a/src/dns-protocol.h
+++ b/src/dns-protocol.h
@@ -144,5 +144,9 @@
   (!CHECK_LEN(header, pp, plen, len) ? 0 : (((pp) += (len)), 1))
 
 /* Escape character in our presentation format for names.
-   Cannot be '.' or /000 and must be !isprint() */
+   Cannot be '.' or /000 and must be !isprint().
+   Note that escaped chars are stored as
+   <NAME_ESCAPE> <orig-char+1>
+   to ensure that the escaped form of /000 doesn't include /000
+*/
 #define NAME_ESCAPE 1