How do I use the JDLRPage setting?

Suppose you have a three-page duplex form (printing on front, back, front), followed by a one page form as a front page form. The second form is printed on the back of the previous form if the JDLRPage setting was not remarked out. In other words:

With JDLRPage setting:

Form 1 (set to duplex): pg1 front, pg1 back, pg2 front 
Form 2 (set as front): pg2 back

Without JDLRPage setting:

Form 1 (set to duplex): pg1 front, pg1 back, pg2 front 
Form 2 (set as front): pg3 front

And, the JDLRPage setting was 0,5,EQ,X'FFFF26FFFF'

The key is that if you use…

JDLRPage = 0,5,EQ,X'FFFF26FFFF' 

you must have your JSL set up so that it has matching RPAGE commands.