Subject: PMP> Re: IPP> RE: Media Names, case sensitivity

From: "Harry Lewis" <[email-masked]>
Date: Tue, 3 Apr 2001 08:31:46 -0600

I suggest something more compact like - 

"Media Size Self Describing Names are not case sensitive. As a convention, 
they
are presented here using lower case characters. Other referencing standards
may impose case sensitive rules across their own interface. For 
interoperability and implementation
efficiency, imposing case sensitivity is not recommended. "
---------------------------------------------- 
Harry Lewis 
IBM Printing Systems 
---------------------------------------------- 

"Hastings, Tom N" <[email-masked]>
Sent by: [email-masked]
04/02/2001 05:51 PM

        To:     "Bergman, Ron" <[email-masked]>
        cc:     "[email-masked]'" <[email-masked]>, "[email-masked]'" <[email-masked]>, 
"[email-masked]'" <[email-masked]>, "pmp (E-mail)" <[email-masked]>
        Subject:        IPP> RE: Media Names, case sensitivity

Ron,

About case sensitivity in names in the Media standard: 

Draft 0.3 had:

Media Size Self Describing Names are not case sensitive but will always be
presented in this standard using lower case characters.

What I changed it to was:

While Media Size Self Describing Names are presented in this standard 
using
lower case characters, other standards that use these names, MUST indicate
the case sensitivity for their conformance.  Such other standards MAY:

a)               also require only lower case as in this standard
b)               allow lower, upper case, and mixed case to be used with 
the same
meaning as the names in this standard, i.e., case insensitive matching
c)               require all uppercase letters to be used with the same 
meaning as
the corresponding names in this standard.

Discussion:

The important question is what interface is the media standard defining
conformance requirements for?  I had assumed that the media standard was 
NOT
trying to define an interface that the Printer would implement or that a
client would implement, but rather was giving a set of names and their
semantics that other standards would reference.  It would be up to these
other standards to say whether or not case was important.  For example, 
IPP
says that keywords are all lower case, so that both client and Printer can
count on having all lower case and not having to worry about case
conversion.  Other protocol, such as the Printer MIB use of MediaType and
UPnP use of MediaType and MediaSize would have to say whether or not case
was important.  We might want the Media standard to RECOMMEND that these
other standards only use all lower case.  That would lower the burden on a
Printer that is supporting, say, IPP, UPnP, and Printer MIB, if all three
standards REQUIRED that the values be all lower case.

BTW, I have seen some IANA Registries where the tokens are all upper case.
That is why I included alternative c) above as well.

Bottom line: The Media standard is writing conformance for other standards
that reference the Media standard (like the IPP Notification Standard 
placed
requirements on Delivery Method documents), not conformance for Printers 
or
clients.

See my replies to your message below preceded by TH>

Comments?

Tom

-----Original Message-----
From: Bergman, Ron [mailto:[email-masked]]
Sent: Monday, April 02, 2001 08:57
To: Hastings, Tom N
Cc: [email-masked]'; [email-masked]'; [email-masked]'
Subject: Media Names, case sensitivity

Tom,

I am curious as to why you changed my original statement that the names 
are
not case sensitive to the the complicated set of requirements that, in
effect,
states "do whatever you want, but explicitly state what you want."

TH> The draft is stating that other standards that use these names do what
they want, but those standards (such as IPP, UPnP, Printer MIB, etc.) MUST
say what they require.

Your specification puts a larger burden on the Printer, since the printer
will
have to conform to the applications.  (The printer may have to do a case
conversion for some applications and not others.)  So the printer (or 
other
device) must know the exact format required by the application.

TH> The Printer will have to conform to whatever standards the Printer
chooses to support, i.e., IPP, UPnP, Printer MIB, ...

Just stating the names are not case sensitive, puts the burden on the
client.

TH> I disagree.  It depends on what the other standards say about case
sensitivity.  Perhaps the Media standard can RECOMMEND that other 
standards
REQUIRE all lower case, as I suggested above.  Wouldn't that help?

But the client simply has to do a conversion on all names received to
whatever
case he has chosen for his tables.  The client does not need to know what
the printer is sending.

Whatever we conclude,, this text needs will be moved from section 5 to 
section 10, since it applies to all the names in the specification.

TH> I agree it should be moved to a section that is common for all the
names.  However, section 10 is the authors section.

    Ron