Program 2. Snippet of PPD file.

*OpenUI *InputSlot: PickOne
*OrderDependency: 15 AnySetup *MediaType
*DefaultInputSlot: Upper
*InputSlot Upper: " 0 statusdict /setpapertray get exec"
*InputSlot Lower: " 1 statusdict /setpapertray get exec"
*InputSlot Envelope: " 2 statusdict /setpapertray get exec"
*?InputSlot: "
 save
  3 dict
   dup /0 (Upper) put
   dup /1 (Lower) put
   dup /2 (Envelope) put
   statusdict /papertray get exec
   {get} stopped {pop pop (Unknown)} if = flush
  restore"
*End
*CloseUI: *InputSlot

