Re: proposed HTTP changes for charset

The current HTTP/1.1 spec:

> The "charset" parameter is used with some media types to define the
> character set (section 3.4) of the data. When no explicit charset
> parameter is provided by the sender, media subtypes of the "text" type
> are defined to have a default charset value of "ISO-8859-1" when
> received via HTTP. Data in character sets other than "ISO-8859-1" or its
> subsets MUST be labeled with an appropriate charset value.

I sent a proposed revision, but I see that my proposal had some
problems. Taking a suggested rewording from Harald and an addition
from Keith, and working on the wording for a while, I've come up with
the following revised proposal, which is that we LEAVE the above
paragraph and add the following note:

# Some HTTP/1.0 servers have sent a Content-Type header of a subtype
# "text", without a charset parameter, to mean "recipient should
# guess".  This is inappropriate behavior, and HTTP/1.1 servers MUST
# NOT omit the charset parameter of text media unless the charset of
# the data is ISO-8859-1 (or the US-ASCII subset).
#
# Unfortunately, some older HTTP/1.0 clients unfortunately did not
# deal properly with an explicit charset parameter.  Senders MAY
# include a charset= parameter even when the charset is ISO-8859-1;
# doing so is RECOMMENDED when it is known that it will not confuse
# the recipient.  HTTP/1.1 recipients MUST respect the charset label
# provided by the sender; those user agents that have a provision to
# "guess" a charset MUST use the charset from the content-type field
# if they support that charset, rather than the recipient's
# preference, when initially displaying a document.

It is my belief that this addition satisfies the desire to encourage
explicit labelling, does not allow omission of the label when it is
necessary to disambiguate it from the default, encourages the sending
of the label in any case where it won't cause confusion, and requires
HTTP/1.1 recipients to deal with the charset label in a way that is
unambigous.

It is my belief that this deals with the objections given to the
initial complaint and is consistent with the opinions expressed so
far, that is, it represents a clarification of the previous consensus
of the working group, and I will represent this as fact to the IESG.

Larry

Received on Wednesday, 3 July 1996 14:42:05 UTC