add comment on uri-parser

scheme/lib/uri.scm

@@ -18,6 +18,12 @@
 
 (define uri-reserved-sans-= (char-set-delete uri-reserved #\=))
 
+;;; Note: this "uri-parser" has never been adapted to RCF 2396 
+;;; (Uniform Resource Identifiers: Generic Syntax)
+;;; It is rather useless by now since it's hard to determine
+;;; exactly which subset of RFC 2396's URIs it works for
+;;;(plus the subset it works for is a rather arbitrary one).
+
 (define (parse-uri s)
   (let* ((slen (string-length s))
 	 ;; Search forwards for colon (or intervening reserved char).