Document the 'URL' argument.

usr.bin/fetch/fetch.1

@@ -1,5 +1,5 @@
 .\"-
-.\" Copyright (c) 2000-2011 Dag-Erling Smørgrav
+.\" Copyright (c) 2000-2012 Dag-Erling Smørgrav
 .\" All rights reserved.
 .\" Portions Copyright (c) 1999 Massachusetts Institute of Technology; used
 .\" by permission.
@@ -29,7 +29,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 27, 2011
+.Dd February 28, 2012
 .Dt FETCH 1
 .Os
 .Sh NAME
@@ -214,6 +214,11 @@ When the
 flag is specified, wait this many seconds between successive retries.
 .El
 .Pp
+.Ar URL
+.Bd -literal
+    <scheme>:(//(<user>(:<pwd>)?@)?<host>(:<port>)?)?/(<document>)?
+.Ed
+.Pp
 If
 .Nm
 receives a