[tex-k] dvips PostScript paper size commands revisted

[M. Shell]

 The dvips manual and info pages make the following statement:


 "Executing the `letter' or `a4' or other PostScript operators cause
  the document to be nonconforming and can cause it not to print on
  certain printers, so the default paper size should not execute such an
  operator if at all possible."


Now, is this still considered to be true? If so, in what way is a
document that contains say, the "a4" PostScript operator nonconforming?

After all, "letter" and "a4" are considered to be valid PostScript
operators - Adobe made them for a reason.

Is it nonconforming in the sense that a .ps file with the "letter"
operator will/may not print on a printer with only A4 paper? i.e.,
Is OK to use the operators if we *know* what paper will be used
during print?

Or is it nonconforming in the sense that some PostScript interpreters
error out when they see such an operator? If so, which ones are
known to have done this and how old are they?


The reason that I bring this up is that if a .ps file is made with
something like:

dvips -t A4size -o myfile.ps myfile

(which does not put in the PostScript operator a4)
and then this file is opened in gv, gv will not report the 
the paper size, but will display BBox (The bounding box). 
The BBox is of the correct dimensions of course - if I 
manually select "A4" in gv, then there will be no visible
change in the display (BBox size = A4 size, which is correct)

When this file is then converted to PDF using Ghostscript:

ps2pdf myfile.ps myfile.pdf

and then viewed under Acrobat Reader (4.0.5 under Linux), Acrobat
reader will open with a display window in US letter paper size -
and I cannot seem to find a way to tell it I want an A4 window size.


Now, if I instead do:

dvips -t a4 -o myfile.ps myfile

(which puts in the a4 operator)
Then both gv and Acrobat Reader see that is A4 paper - gv displays
"A4" rather than "BBox" and Acrobat Reader gives me a display
window with A4 dimensions - which seems to be more proper.

So, why should we not make PS files with explicit paper size
PostScript operators if these operators appear to be so 
helpful in telling all the devices that handle the (PS and PDF)
files what kind of paper size is desired by the document?


 Thanks yet again,

 Mike Shell
 mshell@ece.gatech.edu


PS: FWIW, the relevant lines of my config.ps are:

@ A4size 210mm 297mm
@+ %%PaperSize: A4

@ a4 210mm 297mm
@+ ! %%DocumentPaperSizes: a4
@+ %%BeginPaperSize: a4
@+ a4
@+ %%EndPaperSize