:overflow pdl: [MIT] n. 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}'.
-- The AI Hackers Dictionary