-/* returns a maximum estimate for the space that is needed to store
- * this key in a DNS packet */
-guint avahi_key_get_estimate_size(AvahiKey *k);
+/** Returns a maximum estimate for the space that is needed to store
+ * this key in a DNS packet. */
+size_t avahi_key_get_estimate_size(AvahiKey *k);
+
+/** Returns a maximum estimate for the space that is needed to store
+ * the record in a DNS packet. */
+size_t avahi_record_get_estimate_size(AvahiRecord *r);
+
+/** Do a mDNS spec conforming lexicographical comparison of the two
+ * records. Return a negative value if a < b, a positive if a > b,
+ * zero if equal. */
+int avahi_record_lexicographical_compare(AvahiRecord *a, AvahiRecord *b);
+
+/** Return 1 if the specified record is an mDNS goodbye record. i.e. TTL is zero. */
+int avahi_record_is_goodbye(AvahiRecord *r);