From: Erland Sommarskog (sommar@algonet.se)
Date: Tue Dec 26 2000 - 13:22:53 CST
Charles Lindsey <chl@clw.cs.man.ac.uk> writes:
> Posters SHOULD avoid using control characters in US-ASCII (or other
> CCSs) except for tab (ASCII 9), formfeed (ASCII 12), and backspace
> (ASCII 8). Tab signifies sufficient horizontal white space to reach
> the next of a set of fixed positions; posters are warned that there
> is no standard set of positions, so tabs should be avoided if precise
> spacing is essential. Formfeed (which is sometimes referred to as the
> "spoiler character") signifies a point at which a reading agent
> SHOULD pause and await reader interaction before displaying further
> text. Backspace SHOULD be used only for underlining, done by a
> sequence of underscores (ASCII 95) followed by an equal number of
> backspaces, signifying that the same number of text characters
> following are to be underlined. Posters are warned that underlining
> is not available on all output devices and is best not relied on for
> essential meaning. Reading agents SHOULD recognize underlining and
> translate it to the appropriate commands for devices that support it.
> Reading agents MUST NOT pass other control characters or escape
> sequences unaltered to the output device.
> [X10. Everybody happy to leave those SHOULDs?]
The second and fourth SHOULD ought to be Ought, as far as I can see.
Or is this formatting stuff to be considered as being interoperability
issue?
> 4.3.2. Body Conventions
>
>
> It is a common practice for followup agents to enable the
> incorporation of the followed-up article (the "precursor") as a
> quotation. This SHOULD be done by prefacing each line of the quoted
> text (even if it is empty) with the character ">" (or perhaps with
> "> " in the case of a previously unquoted line). This will result in
> multiple levels of ">" when quoted content itself contains quoted
> content, and it will also facilitate the automatic analysis of
> articles.
>
> NOTE: Posters should edit quoted context to trim it down to the
> minimum necessary. However, followup agents Ought Not to attempt
> to enforce this beyond issuing a warning (past attempts to do so
> have been found to be notably counter-productive).
> [X11. was SHOULD NOT]
The first SHOULD is an obvious case of Ought. At least I fail to see
that we can convice IETF that an interoperability case at stake.
I don't know what RFC850 said, but already good ol' rn permitted you
to change the quote character, which is highly unrecommendable according
to this writing.
> The attribution MAY contain also a single Newsgroup name (the one
> from which the followup is being made), the precursor's Message-ID
> and/or the precursor's Date and Time. Any of these that are present,
> SHOULD precede the name and/or email address. However, the inclusion
> or not of such fields SHOULD always be under the control of the
> poster.
> [X12. both SHOULD -> Ought???]
Definitely. I fail to see the point with specifying the order of the
attribution line, but I seem to recall that there was a discussion on
this. I don't include message-ID nor date and time in my attribution
lines, so I pass. :-)
>
> A "personal signature" is a short closing text automatically added to
> the end of articles by posting agents, identifying the poster and
> giving his network addresses, etc. If a poster or posting agent does
> append such a signature to an article, it MUST be preceded with a
> delimiter line containing (only) two hyphens (ASCII 45) followed by
> one SP (ASCII 32). The signature is considered to extend from the
> last occurrence of that delimiter up to the end of the article (or up
> to the end of the part in the case of a multipart Mime body).
> Followup agents, when incorporating quoted text from a precursor,
> SHOULD NOT include the signature in the quotation. Posting agents
> Ought to discourage (at least with a warning) signatures of excessive
> length (4 lines is a commonly accepted limit).
> [X13. SHOULD NOT -> Ought Not???
> X14. Ought was SHOULD]
X13 is no interoperability, so it must be Ought Not. In passing, let me
note that some people add a PS after the signature. In this case a news-
reader that strips the signature is a kind of hassle. Then again, people
who quote signatures are not my friends.
> NOTE: It is undesirable to have more than one personal signature
> in an article body (even though the rule above admits the
> possibility by recognising only the last one). If, for some
> reason, a second signature is considered necessary, it MAY be
> preceded by a different delimiter (e.g. "--- ").
> [That is Clive's suggestion. Not to be included without further support.
> X15. Please can I take it out now?]
Yes please!
> 4.4. Characters and Character Sets
>
>
> 4.4.2. Character Sets within Article Bodies
>
> Within article bodies, the CES and CCS implied by any Content-
> Transfer-Encoding and Content-Type headers [RFC 2045] SHOULD be
> applied by reading agents. In the absence of such headers, reading
> agents cannot be relied upon to display correctly more than the US-
> ASCII characters.
> [Observe that reading agents are not forbidden to "guess", or to
> interpret as UTF-8 regardless, which would be the simplest course for
> them to take.]
Great wording!
> 4.5. Size Limits
>
> Posting agents SHOULD endeavour to keep all header lines, so far as
> is possible, within 79 characters by folding them at suitable places
> (see 4.2.3). However, posting agents MUST permit the poster to
> include longer headers if he so insists, and compliant software MUST
> support headers of at least 998 octets. Likewise, injecting agents
> SHOULD fold any headers generated automatically by themselves.
> Relaying agents MUST NOT fold headers (i.e. they must pass on the
> folding as received).
> [X17. 1st SHOULD -> Ought??
> X18. 2nd SHOULD -> Ought???]
I don't mind leaving them as SHOULD. But I could live with Ought,
>
> In plain-text messages (those with no Mime headers, or those with a
> Mime Content-Type of text/plain) posting agents Ought to endeavour to
> keep the length of body lines within some reasonable limit. The size
> of this limit is a matter of policy, the default being to keep within
> 79 characters at most, and preferably within 72 characters (to allow
> room for quoting in followups). Exceptionally, posting agents Ought
> Not to adjust the length of quoted lines in followups unless they are
> able to reformat them in a consistent manner. Moreover, posting
> agents MUST permit the poster to include longer lines if he so
> insists.
> [X19. both Oughts were SHOULDs]
Obvious cases.
-- Erland Sommarskog, Stockholm, sommar@algonet.se I'm not in love. It's not even a phase I'm going through.