W3C home > Mailing lists > Public > ietf-http-wg-old@w3.org > September to December 1995

Re: Comments on HTTP/1.0 Draft 3

From: Roy Fielding <fielding@beach.w3.org>
Date: Wed, 20 Sep 1995 23:53:17 -0400
Message-Id: <199509210353.XAA14764@beach.w3.org>
To: JP.Martin-Flatin@ecmwf.int
Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
Hooo boy, many detailed comments.  Before I get into the nitty-gritty,
let's get one thing straight.

   HTTP/1.0 is being submitted as a BCP (Best Current Practices)
   BCPs are not Internet Standards -- In fact, they are explicitly
   forbidden from becoming an Internet Standard.

HTTP/1.1 will (eventually) be submitted as a standards track document.
Aside from backwards-compatibility issues, the two specifications
define separate and distinct protocols.

>Here are some comments on HTTP 1.0 Draft 3, referencing the PostScript
>version. I've tried to sort them in 5 categories: <Problem>, <Why>,
><Edit>, <Comment> and <Pedantic> to help you browse through them.

That's nice.

>## 1 ##
><Comment>
>As a general rule, we should have less "should" and more "must" in this
>spec. ....

*bzzzt* did I mention "general rules" are out of order for HTTP/1.0?
However, this will be done for HTTP/1.1 (in fact, I did it last weekend).

>## 2 ##
><Why>
>Page 4, section 1.1, first paragraph:
>"This specification is not intended to become an Internet standard".
>Why ? FTP is a standard, Telnet is a standard, why shouldn't HTTP
>become one ?

Read the archives regarding the HTTP/1.0 and 1.1 split.

>## 3 ##
><Pedantic>
>Page 4, section 1.2, first paragraph:
>"metainformation" should read "meta-information". The same correction
>should be made page 5, definition of entity, page 19, section 5.2.2,
>lines 2 and 4, page 22, last line before section 6.2.1, page 23, last
>line but one, page 27, section 7.1, line 1.

Nope, sorry, but that is a word I know quite intimately, and I've already
set precedent for its use without a hyphen.

>## 4 ##
><Edit>
>Page 5, definition of server:
>"A program that accepts connections in order to service requests by
>sending back responses". We should add after this sentence: "A server
>can be an origin server, a proxy or both".

That would be an insufficent definition.  The word "server" is defined
correctly.

>## 5 ##
><Edit>
>Page 5, definition of proxy:
>We should remove the last sentence: "Some proxy servers also act as origin
>servers". It's confusing in this context, and #4 makes this point clear.

No, but I have already added different stuff for 1.1.

>## 6 ##
><Pedantic>
>Page 6, definition of #rule, line 3:
>"and optional linear whitespace (LWS)". To be consistent with the rest of
>section 2.1, this should read "and optional linear whitespace characters
>(LWS)".  Same correction page 7, section implied*LWS, line 2.

No, LWS == linear whitespace;   LWS != linear whitespace characters.
Linear whitespace characters are what make up the content of LWS.

>## 7 ##
><Edit>
>Page 7, section 2.2, line 2:
>We should add at the end of the first paragraph something like:
>"Throughout this document, BNF definitions are not given in the usual top
>to bottom manner, i.e. definitions are not only based on reserved words
>previously defined, but also use reserved words defined further on in the
>text. This was deemed to improve the clarity of the whole document".

BNF definitions are never given "in the usual top to bottom manner".
BNF is a mathematical formulism, not a programming language, and is
not order-dependent.

>## 8 ##
><Why>
>Page 7, section 2.2, definition of LWS:
>Why do we have [CRLF] ? Are there > 80% of the WWW applications using
>CRLF as a linear whitespace character ? I doubt it. Page 16 section 4.2,
>it says: "Header fields can be extended over multiple lines by preceding
>extra line with at least one LWS, though this is not recommended". Better
>than not recommended, this should be forbidden by the protocol. Instead,
>a mention to this isue on page 43 section B ("Tolerant applications")
>would be a better idea. What is the rationale for allowing it ?

These issues have already been decided on the WG mailing list.
No change will be made unless consensus is clear to change it.

>## 9 ##
><Why>
>Page 7, section 2.2, definition of tspecials:
>What does the "t" stand for in the reserved word "tspecials" ?

Token (it's from MIME)

>## 10 ##
><Pedantic>
>Page 7, section 2.2, definition of tspecials:
>Rather than 4 lines, this could be compressed in 2 lines. The same comment
>applies to many other BNF definitions. This would make the whole document
>more concise.

Nope, see the text format (the definitive version for RFCs).

>## 11 ##
><Pedantic>
>Page 8, line 5:
>"any text" is confusing: "text" is a reserved word here, and refers to the
>BNF definition further on. It's not the common word "text". This could be
>made more explicit by using a different typography for reserved words,
>e.g. italics.

It is already in the BNF, so it must be a BNF word.  This is exactly
how the words are used in RFC 822 definitions.  Besides, you cannot put
italics in a text/plain document.

>## 12 ##
><Edit>
>Page 8, last but one line:
>"Recipients... may assume that they represent ISO-8859-1 characters".
>It's not "may", it's either "should" or "must". I'd vote for "must".

Nope, the correct word is "may" (i.e., it is optional).

>## 13 ##
><Edit>
>Page 10, section 3.2.1, definition of scheme:
>Do we really need to allow "+", "-" and "." in a scheme name ?
>I don't think so. ALPHA and DIGIT are enough.

Not our turf -- see the ex-URI WG.

>## 14 ##
><Edit>
>Page 10, last but one line:
>Typo: in "and HTTP proxies may receive requests for URLs", "proxies"
>should clearly read "servers".

No, I meant proxies.  You cannot send a URN to just any server.

>## 15 ##
><Edit>
>Page 11, section 3.2.2:
>The trailing slash to indicate the default page of a server (e.g.
>http://www.w3.org/ as opposed to http://www.w3.org) should be mandatory
>for clients, and servers should apply the robustness principle, i.e.
>understand URIs without a trailing slash and add one. The current wording
>is a bit vague on this issue.

<http://www.w3.org> is a valid HTTP URL.  See RFC 1738 and RFC 1808.

>## 16 ##
><Edit>
>Page 11, section 3.3, second paragraph:
>It should be stated more clearly that the 3rd format (asctime) is obsolete,
>that neither clients nor servers should generate a date in asctime, but
>both should be able to understand it (again, principle of robustness).

It already says that.

>We should also add that the second format (RFC 850/1036) uses 2 digits for
>the year, and with the year 2000 getting close, this format is likely to
>be obsoleted by the next release of HTTP.

It already says that too.  However, HTTP/1.0 cannot prescribe HTTP/1.1.

>## 17 ##
><Edit>
>Page 11, definitions of rfc1123-date and rfc850-date:
>To be consistent, we should name them either rfc1123-date and rfc1036-date
>or rfc822-date and rfc850-date. The current names are inconsistent.

You should have put <Pedantic> on that one.  RFC 1036 defines a different
date format than RFC 850 -- the names correctly describe the origin of
the given format.

>## 18 ##
><Edit>
>Page 12, last line before the definition of charset:
>The line "and other names specifically recommended for use within MIME
>charset parameters" should be deleted. This is not an exhaustive list
>of all enabled charsets, but just "the preferred names for those character
>sets most likely to be used".

No, the ISO-2022 and UNICODE names are "specifically recommended for use
within MIME charset parameters".  See the RFCs noted by the Registry.

>## 19 ##
><Edit>
>Page 12, definition of charset:
>"token" should be replaced with "<IANA character set>". It is a bad idea
>not to use the IANA character sets, I can't see the rationale for it. The
>2 sentences following the definition of charset should be replaced with:
>"Applications are encouraged to use the preferred character set names
>listed above, and required to use a character set defined by the IANA
>registry".

This is a protocol definition, not a religious specification.

>## 20 ##
><Edit>
>Page 13, section 3.5, first line:
>Typo: "that has been or can be applied to a resource" should be replaced
>with "that has been applied to a resource". A content coding that "can be"
>applied to a resource is meaningless.

It is a leftover from Accept-Encoding, and I'd rather not remove it.

>## 21 ##
><Why>
>Page 13, section 3.6, line 6-7:
>"because it does not restrict itself to the official IANA and x-token
>types". Why ? What's the rationale ?

See the mailing list archive.

>## 22 ##
><Edit>
>Page 13, section 3.6, after definition of subtype:
>We should add the following before "Parameters may follow...":
>"HTTP/1.0 uses media-type values in the Content-Type (Section 8.5) header
>field".
>This makes it consistent with section 3.5 and its reference to section 8.3.

Okay, but that is not a substantive change.  I'll change it if I generate
a new draft.

>## 23 ##
><Why>
>Page 15, section 3.6.2, line 2:
>"The multipart types registered by IANA [15] do not have any special
>meaning for HTTP/1.0".
>Why ? This section says that HTTP multipart messages are possible, and
>says further on that "multipart body-parts may contain HTTP header fields
>which are significant to the meaning of this part". But the definition
>of Full-Request page 18 allows a single {Entity-Header, CRLF,
>Entity-Body}, not multiple ones, so there seems to be a contradiction.
>The multipart issue probably needs further clarification. Is this an
>item for HTTP/1.1 ?

Yes on HTTP/1.1, no on the rest.  MIME multiparts fit just fine
within the Entity-Body -- as it says, HTTP/1.0 does not give them
special treatment.

>## 24 ##
><Pedantic>
>Page 16, section 4.1, line 7:
>Typo: "a.k.a." should be expanded to "also known as": this is a formal
>spec !

Its an IETF formal spec -- you should be happy I don't follow all of
the IETF traditions.

>## 25 ##
><Edit>
>Page 16, section 4.2:
>Several points are not covered here. We should add the following to this
>section:
>"No header field has a default value, except Date: (Section 8.6). If a
>field-value is specified without a field-content, it should be ignored.
>The field-name is case-insensitive. If a field-name appears in more
>than one header field, then the whole message should be discarded and
>a 4xx or 5xx error returned".

Rubbish. Those additions are not true of of all HTTP/1.0 header fields.

>## 26 ##
><Edit>
>Page 17, first line:
>Typo: "The order in which header fields are received is not significant":
>"received" should read "sent", cf next sentence.

Nope, significance is based on receiving, whereas we can be prescriptive
only on sending.

>## 27 ##
><Edit>
>Page 17, lines 5-6:
>If we trust section 3.6.2 that "multipart body-parts may contain HTTP
>header fields", then this sentence is wrong: in each part of a
>multipart message, we could have the same HTTP header field.

Section 3.6.2 also says " which are significant to the meaning of that
part."  The sentence is correct.

>## 28 ##
><Problem>
>Page 17, section 4.3:
>"There are a few headers... which do not apply to the communicating
>parties or the content being transferred". MIME-Version is surely
>concerned in the content being transferred, so there's a problem here !

No it isn't -- it only defines the format of the message.

>## 29 ##
><Problem>
>Page 17:
>Should a maximum length be defined for the HTTP header = General-Header
>+ Response-Header + Entity-Header + {Request-Line|Status-Line}, say 4KB ?
>That would ensure that a server cannot get stuck reading an infinite HTTP
>header from a bogus client.

No.

>## 30 ##
><Why>
>Page 18, section 5.2, line 2:
>"The method is case-sensitive". Why ? Why couldn't we accept Get, Head
>and Post for instance ? Almost everything else is case-insensitive, why
>be more restrictive here ?

Because that is how it has been defined.  The reason is because the
server may be acting as a gateway to an object server which does have
case-sensitive methods (as do most object servers).

>## 31 ##
><Edit>
>Page 21, section 6.1, definition of Status-Line:
>The Reason-Phrase should really be optional, i.e. the BNF should read:
>Status-Line    = HTTP-Version SP Status-Code [SP Reason-Phrase] CRLF
>This is even implied next page: "since that entity is *likely* to include
>human-readable information".

The SP is required, and Reason-Phrase is already = *<...>,
which is the same as being optional.

>## 32 ##
><Pedantic>
>Pages 22-26:
>Sections 6.2.1 through 6.2.5 should be moved to chapter 8: chapters
>4-5-6-7 are not in-depth, chapter 8 is.

I don't see any advantage to doing that, particularly not now.

>## 33 ##
><Edit>
>Page 23, definition of 201, line 4:
>"or within a clearly defined timeframe": how can the client learn from
>the server what this "clearly defined timeframe" is ? This is wishful
>thinking: even if it looks like a good idea initially, it's not feasible
>in practice with HTTP/1.0. This should be removed from the spec. This
>may be put back in a later version of HTTP if we add a header field
>for the server to tell the client what this "clearly defined timeframe"
>is at the same time it returns 201.

The "clearly defined timeframe" can be included in the response body.

>## 34 ##
><Edit>
>Page 24, definition of 300, last line:
>"user agents may use the Location value for automatic redirection".
>Read this sentence twice, it's ambiguous and has 2 meanings: what you
>mean is that it can get from the server a Location field. What you can
>also understands is that the client may use the Location field in its
>request, which is wrong. Let you native English speakers devise a new
>unambiguous sentence to replace this one !

No -- there is absolutely nothing ambiguous about it, as would be obvious
if you hadn't quoted only half the sentence.

>## 35 ##
><Problem>
>Page 24, definition of 301, second paragraph:
>The new URL is given twice, once in the Location header field, once in
>the Entity-Body. This is redundant and a loss of bandwidth. It shouldn't
>appear in the Entity-Body, IMHO. Ditto for 302.

And just how do you expect the user to see where the new resource
is located if the client does not support auto-redirect?

THERE SHALL BE NO CHANGES TO THE HTTP/1.0 SPEC WHICH WOULD OBVIOUSLY BREAK
ALL KNOWN IMPLEMENTATIONS OF HTTP/1.0.

>## 36 ##
><Why>
>Page 24, definition of 301, third paragraph:
>"If the 301 status code is received in response to a request using the
>POST method, the user agent must not automatically redirect the request
>unless it can be confirmed by the user, since this might change the
>conditions under which the request was issued."
>What is the rationale ? What practical case do you have in mind ?
>Ditto for 302.

See the mailing list archives.

>## 37 ##
><Edit>
>Page 25, section 6.2.4:
>Line 2, in "should immediately cease", replace "should" with "must".

That would incorrectly describe current implementations.

>Line 3, in "the server is encouraged to include", replace "is
>encouraged to" with "should".
>In the definition of 400, in "The client is discouraged from
>repeating", replace "is discouraged from" with "should not".

Nope, they have the same meaning for a BCP.

>## 38 ##
><Edit>
>Page 25, definition of 401:, line 3:
>Just after "suitable Authorization", we should add "(Section 8.2)".

Another non-substantive change, but okay.

>## 39 ##
><Comment>
>Page 25, definition of 403:
>We lack a status code whereby the server refuses to honor a request,
>but is willing to say why, e.g. "this page is available to internal
>users only". Should we create a new status code for this in HTTP/1.1 ?

You don't need a new status code for that -- just include the reason
in the response body.  The current wording is too restrictive.

>## 40 ##
><Edit>
>Page 26, line 4-5:
>In "it should immediately cease", replace  "should" with "must".

No, as above.

>In "the server is encouraged to include an entity", replace "is
>encouraged to" with "should".

Whatever.

>## 41 ##
><Comment>
>Page 27, definition of Entity-Header:
>Allow is considered as an Entity-Header. Isn't it server-specific rather
>than URI-specific ? In other words, shouldn't it be a Response-Header
>instead ?

No, it can be defined by a creation method in a request (e.g., PUT).

>## 42 ##
><Edit>
>Page 27, section 7.1, last line:
>Add "unmodified" as follows:
>"Unknown header fields should be ignored by the recipient and forwarded
>unmodified by proxies".

No, that is not possible in some circumstances.  Unknown header fields
can always be folded and unfolded.

>## 43 ##
><Pedantic>
>Page 27, section 7.2, second paragraph:
>Line 2, "in general" should be deleted, because it's always the case:
>cf line 4 "must include".

Makes no difference, but okay.

>Line 4, there's a typo: "request message header", singular.

Nope, plural.

>Line 4 again, "HTTP/1.0 requests containing content" doesn't sound
>great: "containing an entity-body" sounds better to me.

Well, it isn't supposed to be a novella.

>## 44 ##
><Edit>
>Page 27, section 7.2, last line:
>"The responses 204 (no content) and 304 (not modified)". Should also add
>"and 403 (forbidden)".

No, 403 contains an entity-body.

>## 45 ##
><Pedantic>
>Page 28, line 4:
>Delete "(i.e. the identity function)", it's dead wood and adds nothing.

In this case, it defines the encoding in mathematical terms.

>## 46 ##
><Edit>
>Page 28, lines 5-6:
>Cf #25 for the default value. Replace lines 5-6 with:
>"All HTTP/1.0 messages with an entity-body must have a Content-Type
>header field. If and only if this header field is not specified, as is
>always the case for HTTP/0.9 messages, the recipient may attempt to
>guess the media type...".

No, that does not match current practice, and would introduce
unnecessary broken behavior.

>Line 8, replace "the receiver should" with "the recipient must".

Receiver should be recipient, yes, but "must" is incorrect.

>## 47 ##
><Pedantic>
>Page 28, section 7.2.2, paragraph 2, line 2-3:
>"containing content" should become "containing an entity-body".

Okay.

>End of line 3, "entity body" should become "entity-body" to be consistent
>with the rest of the document.

Entity-Body is used to refer to the formal BNF definition of an entity body.
One is BNF, the other is English.  I'll get rid of the extra hyphens.

>## 48 ##
><Edit>
>Page 28, last 2 lines:
>"Unless the client knows that it is receiving a response from a compliant
>server, it should not depend on the Content-Length value being correct".
>Argh ! These servers aren't HTTP/1.0 compliant, let's not ask the clients
>to break the protocol to accomodate them ! This sentence should be deleted.
>Maybe replaced with a reminder that clients should be robust, but I doubt
>it, as the rest of the note makes the point clear.

BCP.

>## 49 ##
><Edit>
>Page 28, last line:
>Add a second note:
>"Note: The Content-Length header field must not be specified if there is
>no Entity-Body in the message; in other words, 'Content-Length: 0' is
>invalid."

Not true for methods like HEAD.  Not true in any case, since 0 is valid.

>## 50 ##
><Comment>
>Pages 29-35:
>It would be a good idea to add a line at the beginning of all 8.x sections
>specifying whether this header field may be found in a request or a
>response, e.g.:
>Request: YES     Response: NO
>For the moment, we need to edit the first sentence of most sections 8.x
>to give this information (a few already have it).

Those that apply only to request have "request"; those that apply only
to responses have "response"; all the rest have neither.

>## 51 ##
><Edit>
>Page 29, section 8.1:
>Line 1, add "response" after "Allow".

No, as above.

>Line 4, in "thus should be ignored", replace "should" with "must".

Not necessary.

>Second paragraph, line 2, delete "This field has no default value
>(cf #25).

No.

>Third paragraph, replace "the allow header" with "the Allow header
>field", to remain consistent in terms of terminology.

Okay.

>## 52 ##
><Edit>
>Page 29, section 8.2:
>Beginning of line 1, add: "This is a request header field".

Unnecessary -- it says that already in the first line.

>Last line, replace "Proxies must not cache the response to a request"
>with "Proxies must not cache any HTTP/1.0 message".

No -- the distinction is important.

>## 53 ##
><Edit>
>Page 29, section 8.3:
>Line 1, add "(request or response)" after "header field".

Unnecessary.

>## 54 ##
><Edit>
>Page 30, lines 2-3:
>Delete "or analogous usage". The sentence starts with "Typically", so
>you don't need it.

No, that is not what the "Typically" refers to.

>## 55 ##
><Edit>
>Page 30, section 8.4:
>Line 1, add "(request or response)" after "header field".
>The paragraph after the example is wrong, cf page 20 line 1 (mandatory
>for POST) and page 28 line 17. This paragraph should read instead:
>"Applications must use this field to indicate the size of the Entity-Body
>to be transferred, regardless of the media type of the entity".
>Next line, "greater than or equal to zero" should become "greater than
>zero", cf #49.
>In the Note, line 3, replace "should" with "must". The rationale is that
>it's mandatory, but applications should be robust and not crash if it's
>not there.

No, No, and No.  It is not mandatory, as is painfully evident on
any server known to exist.  It is only required for requests containing
an entity body, and that is adequately covered elsewhere.

>## 56 ##
><Edit>
>Page 30, section 8.5:
>Line 1, add "(request or response)" after "header field".
>After the example, delete "The Content-Type header field has no default
>value", cf #25.

No.

>## 57 ##
><Edit>
>Page 30, section 8.6:
>Line 1, replace "The Date header" with "The Date header field (request
>or response)".

Whether or not "field" is included makes no substantive difference.

>After the example, it states:
>"If a message is received via direct connection with the user agent (in
>the case of requests) or the origin server (in the case of responses),
>then the default date can be assumed to be the current date at the
>receiving end".
>The presence of proxies is irrelevant here. This sentence should be
>replaced with:
>"If a message has no Date header field, then the recipient may assume
>that the default date is the current date at the time the message is
>received".

On the contrary, it is entirely relevant. The date cannot be assumed if
the message was not sent directly from the originator.

>Last line of the page, in "origin servers should always include a Date
>header", replace "should" with "must".

Not true in current practice.

>## 58 ##
><Edit>
>Page 31, section 8.6:
>Line 5, delete first sentence: "Only one Date header field is allowed
>per message" (cf #25).

It is true, though unnecessary.

>## 59 ##
><Edit>
>Page 31, section 8.7:
>Line 1, add "response header" after "Expires".

No, it is an Entity-Header.

>Lines 2-3, replace "Caching clients, including proxies" with "Caching
>clients and proxies".

No, proxies are clients.

>Second paragraph, i.e. after the example, delete sentence "The Expires
>field has no default value" (cf #25).

No.

>End of second paragraph, after "dynamism", we should add: "The Expires
>date should not be earlier than the Date date, but this is not mandatory."
>This is to cope with bogus implementations as explained in the note of
>section 8.7.

That would be incorrect.

>Third paragraph, "The Expires field" should become "The Expires header
>field", for consistency.

Okay.

>## 60 ##
><Edit>
>Page 32, section 8.8:
>Line 1, add "request" after "From".

Line 1 already includes "requesting".

>Line 3, "as updated" becomes "and updated".

No, "as" is the correct word here.

>End of note, add "(Section 8.14)".

There is no reason to include a cross-reference to Referer.

>## 61 ##
><Edit>
>Page 32, section 8.9:
>Line 1, add "request" after "If-Modified-Since".

It is already clear from Line 1 that it is a request header field.

>In a) line 1, replace "200" with "2xx".

No, 200 is correct.

>End of section, add:
>"Note: Servers implementors are encouraged to return responses with a
>status code of 304 quicker (i.e. higher priority) than responses to a
>normal GET or an If-Modified-Since with another status code." Not sure
>many servers already prioritize their responses, but sounds like a good
>idea, as it encourages caching.

"Sounds like a good idea"?  No.

>## 62 ##
><Edit>
>Page 33, section 8.10:
>Line 1, add "response" after "Last-Modified".

No, it is an Entity-Header.

>Line 1, delete "sender believes the", that's dead wood. Nothing is
>"guaranteed" per se, it's always as the client or the server believes
>it.

No, the distinction is important.

>Line 3, replace "receiver" with "recipient" twice (cf terminology at
>the beginning of section 8).

Damn, I could have sworn I did a global search for that ... must've
been for HTTP/1.1.

>Replace last line of section 8.10 with:
>"In such cases, where the resource's last modification time would
>indicate some time in the future (e.g. due to time skew between the
>origin server and a database accessed via a gateway), the server must
>replace that date with the message origination date".

Hey, that's dead wood.  There are a thousand different ways to screw
up the dates, and I'm not going to include them all.

>## 63 ##
><Pedantic>
>Page 33, section 8.12:
>Line 1: replace "MIME-conformant" with "MIME-compliant", to use the same
>expression throughout the spec.

RFC 1521 uses both, though the former more often.  Which is better?

>Line 1, add "(both requests and responses)" after "HTTP/1.0 messages".

Unnecessary.

>Line 9, replace "intended to be MIME-conformant" with "fully
>MIME-compliant".

Whatever.

>## 64 ##
><Edit>
>Page 34, section 8.13:
>Line 1, replace "Pragma message" with "Pragma response".

I'll just cross-out message.  It is a General-Header.

>Line 3, delete "intermediate" (cf terminology section 1.3).
>First line after the definition of extension-pragma, replace
>"intermediary" with "proxy" (cf terminology section 1.3).

Some intermediaries are not proxies.  I have already defined
this better for HTTP/1.1.

>## 65 ##
><Why>
>Page 34, section 8.13, lines 4-5:
>"All pragma directives specify optional behavior from the viewpoint of
>the protocol": why optional rather than mandatory ?

Because that's what "pragma" implies, and that's how it is implemented.
It was originally intended as an implementation-specific directive for
the CERN proxy.  Yeah, I know, bad idea -- but you can blame Ari for
that one. ;-)

>## 66 ##
><Edit>
>Page 34, section 8.14:
>Last line, add "(cf Section 8.8)".

That would only cross-reference to a repeat of the same info --
cross-references should only be used when they indicate something
worth looking at.

>## 67 ##
><Comment>
>Page 35, section 8.15:
>After the example:
>"If the response is being forwarded through a proxy, the proxy
>application should not add its data to the product list".
>In fact, the proxy mustn't overwrite any header field, except the
>HTTP-Version in the Status-Line (cf page 9, last paragraph). So this
>sentence should probably be removed.

It's there for historical reasons.

>Last line of the note: this is security though obscurity. It gives you
>the illusion of being more secure, that's all. If you have a server
>open to the world, it's open for hackers. If they know a loophole to
>break in say NCSA httpd 1.3, they'll try it on your server, whatever
>you return with Server. I don't think there's any point in encouraging
>servers implementors to make Server a configurable option.

This opinion has been proven false on any number of occasions.
Knowing the exact version makes it easier (and thus faster)
for a cracker, and thus makes it easier for them to take advantage
of your server without (or before) being detected.

>## 68 ##
><Edit>
>Page 35, section 8.16:
>Line 1: add "request header" after "User-Agent".

Line 1 already contains two references to that effect.

>Line 4, replace "should always" with "should": again, let's stick to
>the RFCs definitions of must, should and may.

Not a substantive change.

>## 69 ##
><Edit>
>Page 35, section 8.17:
>Line 1, add "response" after "WWW-Authenticate".

Line 1 already contains one reference to that effect.

>## 70 ##
><Edit>
>Page 36, last but one paragraph:
>The second sentence is ambiguous: you want to allow authentication and
>encryption mechanisms which are not at the transport level as well, cf
>IPv6. I suggest to rephrase it like this:
>"Additional authentication and encryption mechanisms may be used, e.g.
>at transport level via message encapsulation, and/or with additional
>headers...".

No, you are misreading the paragraph.  All three mechanism are not defined
by this spec.

>## 71 ##
><Edit>
>Page 36, last but one line:
>Replace "and must not cache a request containing Authorization" with "and
>must not cache a message containing an Authorization or WWW-Authenticate
>header field".

No, requests are never cached.

>## 72 ##
><Comment>
>Page 39, lines 3-4:
>"the Referer field may indicate a private document's URI whose
>publication would be inappropriate".
>If it's private, it's either not accessible to anyone except the owner,
>or not accessible to external users. So there's little risk here, IMHO.

The fact that it exists may be private.

>The real security problem is the weakness of the authentication and
>autorization schemes available in HTTP/1.0, as stated earlier in section
>10. Referer, From and Server are negligible in comparison, I see little
>point in insisting so heavily on them.

Others differ with your opinion.

>## 73 ##
><Pedantic>
>Page 40, line 10:
>Replace "Jean Francois-Groff" with "Jean-Francois Groff".

Drat, how did that one happen?  I must have gone cross-eyed.

>## 74 ##
><Pedantic>
>Page 43, section B, lines 5-6:
>To be consistent with the rest of the document:
>Replace "StatusLine" with "Status-Line".
>Replace "RequestLine" with "Request-Line".

Drat again.

>## 75 ##
><Pedantic>
>Page 44, section C, line 4:
>To be consistent with the rest of the document:
>Replace "MIME-conforming" with "MIME-compliant".
>Ditto page 45, line 2.

Okay.

>## 76 ##
><Comment>
>Page 45:
>The difference between Content-Encoding and Content-Transfer-Encoding is
>not crystal clear (at least to me !). A few words explaining it would be
>welcome in section C.4.

Too late for non-specific additions.

>## 77 ##
><Comment>
>Page 45:
>A section C.5 about multipart could be added, cf #23 and #27.

Multipart is allowed in HTTP/1.0, so there is no reason to highlight it.
The multipart types are just another media type.

 ....Roy T. Fielding  Department of ICS, University of California, Irvine USA
                      Visiting Scholar, MIT/LCS + World-Wide Web Consortium
                      (fielding@w3.org)                (fielding@ics.uci.edu)
Received on Wednesday, 20 September 1995 20:56:21 EDT

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