I am emailing this issue ("What if compression is supplied but not
supported?") to make sure that there is consensus for the editorial change
that we are about to make in the model document for IPP/1.1.
The issue is:
28) ISSUE: What if compression is supplied but not supported?
Possible Alternatives (related to Issues 3 and 6): OPEN - propose to the DL
that "compression" is REQUIRED for IPP/1.1 (with at least the 'none' value),
even though it is OPTIONAL for IPP/1.0.
We propose that 'compression' be required like 'document-format' even if the
only value supported is none because both the compression and the
document-format for a document must be supported by the printer in order for
the document to be processed and printed. The lack of mandated supported
for 'compression' in a printer is a bug in IPP/1.0 and this bug means that a
printer which doesn't support the compression attribute (and ignores it per
IPP rules) may try to process a document that is compressed and therefore
unreadable.
By requiring that a printer support the compression operation attribute, we
must also require support for the 'compression-supported' printer attribute
and we must add 'compression-supported' to the SLP printer template.