usefor-article-13 May 2004

4.2.1.  Naming of Headers

   Despite the restrictions on header-name syntax imposed by the
   grammar, relaying, serving and reading agents SHOULD tolerate
   header-names containing any US-ASCII printable character other than
   colon (":", US-ASCII 58).

   Whilst relaying agents MUST accept, and pass on unaltered, any non-
   variant header whose header-name is syntactically correct, and
   reading agents MUST at least provide the option of displaying them,
   posting and injecting agents SHOULD NOT generate headers other than
     o headers established by this standard or any extension to it;
     o those recognized by other IETF-established standards, notably the
       Email standard [RFC 2822] and its extensions, and included in the
       Permanent Message Header Field Repository maintained by IANA in
       accordance with [KLYNE], but excluding any header explicitly
       deprecated for Netnews (e.g. see section 9.2.1 for the deprecated
       Disposition-Notification-To-header);
     o experimental headers beginning with "X-" (as defined in 4.2.5.1);
     o on a provisional basis only, headers related to new protocols
       under development which are listed in the Provisional Message
       Header Field Repository maintained by IANA in accordance with
       [KLYNE].
   However, software SHOULD NOT attempt to interpret headers not
   specifically intended to be meaningful in the Netnews environment.

   Header-names are case-insensitive. There is a preferred case
   convention set out in [USEAGE], and which is used in the various
   rules defining headers in this standard.  Relaying and reading agents
   MUST, however, tolerate header-names in any case.

--- ../usefor-article-12/Naming_of_Headers.out          November 2003
+++ ../usefor-article-13/Naming_of_Headers.out          May 2004
@@ -7,25 +7,22 @@
 
    Whilst relaying agents MUST accept, and pass on unaltered, any non-
    variant header whose header-name is syntactically correct, and
-   reading agents MUST enable them to be displayed, at least optionally,
+   reading agents MUST at least provide the option of displaying them,
    posting and injecting agents SHOULD NOT generate headers other than
      o headers established by this standard or any extension to it;
      o those recognized by other IETF-established standards, notably the
-       Email standard [RFC 2822] and its extensions, excluding any
-       explicitly deprecated for Netnews (e.g. see section 9.2.1 for the
-       deprecated Disposition-Notification-To-header); or,
-       alternatively, those listed in some future IANA registry of
-       recognized headers;
+       Email standard [RFC 2822] and its extensions, and included in the
+       Permanent Message Header Field Repository maintained by IANA in
+       accordance with [KLYNE], but excluding any header explicitly
+       deprecated for Netnews (e.g. see section 9.2.1 for the deprecated
+       Disposition-Notification-To-header);
      o experimental headers beginning with "X-" (as defined in 4.2.5.1);
      o on a provisional basis only, headers related to new protocols
-       under development which are the subject of (or intended to be the
-       subject of) some IETF-approved RFC (whether Informational,
-       Experimental or Standards-Track).
+       under development which are listed in the Provisional Message
+       Header Field Repository maintained by IANA in accordance with
+       [KLYNE].
    However, software SHOULD NOT attempt to interpret headers not
    specifically intended to be meaningful in the Netnews environment.
-[However, if [KLYNE], which defines an IANA registry of recognized
-headers, becomes accepted before we are done (which is likely), then
-that paragraph can be simplified very considerably.]
 
    Header-names are case-insensitive. There is a preferred case
    convention set out in [USEAGE], and which is used in the various