control characters and Util::clean_text()

[Dennis Melentyev]

Thr, 22/12/2005 в 13:20 +0800, byron wrote:

> RFC1652 (July 1994) introduced 8bit MIME.
This RFC specify that server must accept any bits client will send it.
Do not separating header and body of the message, but there still
RFC822, which denies NON-ASCII characters in headers. And RFC1521 refers
to it in that part. And RFC1522 is more precise, putting all
responsibility onto the mail composers/readers while still talking on
RFC822 (AKA STD11) conformance: 

   A mail composer that implements this specification will provide a
   means of inputting non-ASCII text in header fields, but will
   translate these fields (or appropriate portions of these fields) into
   encoded-words before inserting them into the message header.

   A mail reader that implements this specification will recognize
   encoded-words when they appear in certain portions of the message
   header.  Instead of displaying the encoded-word "as is", it will
   reverse the encoding and display the original text in the designated
   character set.

(See http://www.faqs.org/rfcs/rfc1522.html for details)

> RFC3030 (December 2000) introduced BDAT (binary version of DATA)
> [obsoletes RFC1830 - August 1995].
I'm not sure how widely is it supported. Just don't know that.