Could you elaborate on why you think that the requester needs to be
able to flag each supplied attribute as to whether it is a
compulsory (what you call mandatory) or is non-compulsory (what you
call optional) in order to achieve extensibility.
IPP has dropped the idea of allowing the requester to be able to
indicate. Now IPP requires the provider to reject the request if there
are any values that the provider doesn't understand. The requester
then needs to fix up the request until the provider can accept all
values. The requester can query the provider to determine all supported
values of all attributes that the requester can supply.
At 13:10 06/09/97 PDT, Larry Masinter wrote:
>For good extensibility and interoperability, you need both
>manditory parameters ("reject this job if you don't understand
>this parameter") and optional ones ("if you don't understand
>this, just ignore it").
>>A recipient must be able to tell just by examining the
>attribute which class it is in.
>>I thought this was part of the whole job/PDL parameter override
>issue, but it looks like I must have missed something.