When we assigned enum values for the "orientation" attribute, we started
at 1, instead of 3, since the Job Monitoring MIB doesn't currently
have an orientation attribute. But if we added one to the Job Monitoring
MIB in the future, or a private implementation did, the values would have
to be offset from the IPP values.
To avoid such an implementation nusiance, lets offset the IPP values now,
as if we had obtained them from a MIB. So change 'portrait' to be '3',
'landscape' to be '4', and 'reverse-landscape' to be '5' in section 4.2.10.
Then the enum values will also agree with the note in section 4.1.6 'enum':
Note: SNMP MIBs use '2' for 'unknown' which corresponds to the IPP out of
band value 'unknown'. See the description of the "out-of-band" values at
the beginning of Section Attribute Syntaxes. Therefore, most attributes of
type 'enum' often start at '3'.
In fact, we could delete "most" and "often" in the note, so that it reads:
Therefore, attributes of type 'enum' start at '3'.
since there are no other enum attributes that use '1' and '2' values
and there shouldn't be any in the future either.
Here is the current text for the "orientation" attribute:
4.2.10 orientation (type2 enum)
This attribute specifies the orientation of the content of the print-stream
pages to be printed. In most cases, the orientation of the content is
specified within the document format generated by the device driver at
print time. However, some document formats (such as 'text/plain') do not
support the notion of page orientation, and it is possible to bind the
orientation after the document content has been generated. This attribute
provides an end user with the means to specify orientation for such documents.
Standard values are:
Value Symbolic Name and Description
'1' 'portrait': The content will be imaged across the short edge of the
medium.
'2' 'landscape': The content will be imaged across the long edge of the
medium. Landscape is defined to be a rotation of the print-stream page to
be imaged by +90 degrees with respect to the medium (i.e. anti-clockwise)
from the portrait orientation. Note: The +90 direction was chosen because
simple finishing on the long edge is the same edge whether portrait or
landscape
'3' 'reverse-landscape': The content will be imaged across the long edge
of the medium. Reverse-landscape is defined to be a rotation of the
print-stream page to be imaged by -90 degrees with respect to the medium
(i.e. clockwise) from the portrait orientation. Note: The
'reverse-landscape' value was added because some applications rotate
landscape -90 degrees from portrait, rather than +90 degrees.
Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
multiple-document-handling (type2 keyword)) and the relationship of this
attribute and the other attributes that control document processing is
described in section Using Job Template Attributes During Document
Processing..