Computer Dictionary of Information Technology

overflow pdl

The place where you put things when your pdl is full. If you don't have one and too many things get pushed, you forget something. The overflow pdl for a person's memory might be a memo pad. This usage inspired the following doggerel:

 Hey, diddle, diddle
 The overflow pdl
   To get a little more stack;
 If that's not enough
 Then you lose it all,
   And have to pop all the way back.
			       --The Great Quux

The term pdl seems to be primarily an MITism; outside MIT this term is replaced by "overflow stack".