usefor-article-07 May 2002

3.2.  Transitional Arrangements

   An important distinction must be made between serving and relaying
   agents, which are responsible for the distribution and storage of
   news articles, and user agents, which are responsible for
   interactions with users. It is important that the former should be
   upgraded to conform to this standard as soon as possible to provide
   the benefit of the enhanced facilities.  Fortunately, the number of
   distinct implementations of such agents is rather small, at least so
   far as the main "backbone" of Usenet is concerned, and many of the
   new features are already supported. Contrariwise, there are a great
   number of implementations of user agents, installed on a vastly
   greater number of small sites. Therefore, the new functionality has
   been designed so that existing agents may continue to be used,
   although the full benefits may not be realised until a substantial
   proportion of them have been upgraded.

   In the list which follows, care has been taken to distinguish the
   implications for both kinds of agent.

     o [RFC 2822] style comments in headers do not affect serving and
       relaying agents (note that the Newsgroups-, Distribution- and
       Path-headers do not contain them). They are unlikely to hinder
       their proper display in existing reading agents except in the
       case of the References-header in agents which thread articles.
       Therefore, it is provided that they SHOULD NOT be generated
       except where permitted by the previous standards.
     o Because of its importance to all serving agents, the extension
       permitting whitespace and folding in Newsgroups-headers SHOULD
       NOT be used until it has been widely deployed amongst relaying
       agents. User agents are unaffected.
     o The new style of Path-header is already consistent with the
       previous standards. However, the intention is that relaying
       agents should eventually reject articles in the old style, and so
       this possibility should be offered as a configurable option in
       relaying agents. User agents are unaffected.
     o The vast majority of serving, relaying and transport agents are
       believed to be already 8bit clean (in the slightly restricted
       sense in which that term is used in the MIME standards). User
       agents that do not implement MIME may be disadvantaged, but no
       more so than at present when faced with 8bit characters (which
       currently abound in spite of the previous standards).
     o The introduction of MIME reflects a practice that is already
       widespread.  Articles in strict compliance with the previous
       standards (using strict US-ASCII) will be unaffected. Many user
       agents already support it, at least to the extent of widely used
       charsets such as ISO-8859-1. Users expecting to read articles
       using other charsets will need to acquire suitable reading
       agents. It is not intended, in general, that any single user
       agent will be able to display every charset known to IANA, but
       all such agents MUST support US-ASCII. Serving and relaying
       agents are not affected.
     o The use of the UTF-8 charset for headers will not affect any
       existing usage that complies with the previous standards, since
       US-ASCII is a strict subset of UTF-8. Insofar as newsgroup names
       containing non-ASCII characters can now be expected to arise,
       some support from serving and relaying agents will be desirable,
       although it has been established that most current serving agents
       can already cope with such names without modification (although
       perhaps not in an ideal manner). Note that it is not necessary
       for serving and relaying agents to understand all the characters
       available in UTF-8, though it is desirable for them to be
       displayable for diagnostic purposes via some escape mechanism
       using, for example, the visible subset of US-ASCII. For users
       expecting to use the more exotic possibilities available under
       UTF-8, the remarks already made in connection with MIME will
       apply.
     o The new Control: mvgroup command will need to be implemented in
       serving agents. For the benefit of older serving agents it is
       therefore RECOMMENDED that it be followed shortly by a
       corresponding newgroup command and it MUST always be followed by
       a rmgroup command for the old group after a reasonable overlap
       period. An implementation of the mvgroup command as an alias for
       the newgroup command would thus be minimally conforming. User
       agents are unaffected.
     o All the headers newly introduced by this standard can safely be
       ignored by existing software, albeit with loss of the new
       functionality.

--- ../usefor-article-06/Transitional_Arrangements.out          November 2001
+++ ../usefor-article-07/Transitional_Arrangements.out          May 2002
@@ -1,14 +1,14 @@
 3.2.  Transitional Arrangements
 
    An important distinction must be made between serving and relaying
-   agents which are responsible for the distribution and storage of news
-   articles, and user agents which are responsible for interactions with
-   users. It is important that the former should be upgraded to conform
-   to this standard as soon as possible to provide the benefit of the
-   enhanced facilities.  Fortunately, the number of distinct
-   implementations of such agents is rather small, at least so far as
-   the main "backbone" of Usenet is concerned, and many of the new
-   features are already supported. Contrariwise, there are a great
+   agents, which are responsible for the distribution and storage of
+   news articles, and user agents, which are responsible for
+   interactions with users. It is important that the former should be
+   upgraded to conform to this standard as soon as possible to provide
+   the benefit of the enhanced facilities.  Fortunately, the number of
+   distinct implementations of such agents is rather small, at least so
+   far as the main "backbone" of Usenet is concerned, and many of the
+   new features are already supported. Contrariwise, there are a great
    number of implementations of user agents, installed on a vastly
    greater number of small sites. Therefore, the new functionality has
    been designed so that existing agents may continue to be used,
@@ -19,21 +19,21 @@
    implications for both kinds of agent.
 
      o [RFC 2822] style comments in headers do not affect serving and
-       relaying agents (note that the Newsgroups and Path headers do not
-       contain them). They are unlikely to hinder their proper display
-       in existing user agents except in the case of the References
-       header in agents which thread articles. Therefore, it is provided
-       that they SHOULD NOT be generated except where permitted by the
-       previous standards.
+       relaying agents (note that the Newsgroups-, Distribution- and
+       Path-headers do not contain them). They are unlikely to hinder
+       their proper display in existing reading agents except in the
+       case of the References-header in agents which thread articles.
+       Therefore, it is provided that they SHOULD NOT be generated
+       except where permitted by the previous standards.
      o Because of its importance to all serving agents, the extension
-       permitting whitespace and folding in Newsgroup headers SHOULD NOT
-       be used until it has been widely deployed amongst relaying
+       permitting whitespace and folding in Newsgroups-headers SHOULD
+       NOT be used until it has been widely deployed amongst relaying
        agents. User agents are unaffected.
-     o The new style of Path header is already consistent with the
+     o The new style of Path-header is already consistent with the
        previous standards. However, the intention is that relaying
        agents should eventually reject articles in the old style, and so
-       this should be offered as a configurable option for relaying
-       agents. User agents are unaffected.
+       this possibility should be offered as a configurable option in
+       relaying agents. User agents are unaffected.
      o The vast majority of serving, relaying and transport agents are
        believed to be already 8bit clean (in the slightly restricted
        sense in which that term is used in the MIME standards). User
@@ -51,25 +51,29 @@
        all such agents MUST support US-ASCII. Serving and relaying
        agents are not affected.
      o The use of the UTF-8 charset for headers will not affect any
-       existing usage, since US-ASCII is a strict subset of UTF-8.
-       Insofar as newsgroup names containing non-ASCII characters can
-       now be expected to arise, support from serving and relaying
-       agents will be necessary. It is believed that the customary
-       storage structure used by serving agents can already cope
-       (perhaps not ideally) with such names. Note that it is not
-       necessary for serving and relaying agents to understand all the
-       characters available in UTF-8, though it is desirable for them to
-       be displayable for diagnostic purposes via some escape mechanism
+       existing usage that complies with the previous standards, since
+       US-ASCII is a strict subset of UTF-8. Insofar as newsgroup names
+       containing non-ASCII characters can now be expected to arise,
+       some support from serving and relaying agents will be desirable,
+       although it has been established that most current serving agents
+       can already cope with such names without modification (although
+       perhaps not in an ideal manner). Note that it is not necessary
+       for serving and relaying agents to understand all the characters
+       available in UTF-8, though it is desirable for them to be
+       displayable for diagnostic purposes via some escape mechanism
        using, for example, the visible subset of US-ASCII. For users
        expecting to use the more exotic possibilities available under
        UTF-8, the remarks already made in connection with MIME will
        apply.
      o The new Control: mvgroup command will need to be implemented in
-       serving agents. It SHOULD be used in conjunction with pairs of
-       matching rmgroup and newgroup commands (injected shortly after
-       the mvgroup) until such time as mvgroup is widely implemented.
-       User agents are unaffected.
-     o The headers newly introduced by this standard can safely be
+       serving agents. For the benefit of older serving agents it is
+       therefore RECOMMENDED that it be followed shortly by a
+       corresponding newgroup command and it MUST always be followed by
+       a rmgroup command for the old group after a reasonable overlap
+       period. An implementation of the mvgroup command as an alias for
+       the newgroup command would thus be minimally conforming. User
+       agents are unaffected.
+     o All the headers newly introduced by this standard can safely be
        ignored by existing software, albeit with loss of the new
        functionality.