Basically POOL ID is a random token id given for a group of RULES RUNNING IN background. When u want to load datapage that is being used in batch processing ( by agent). u enter this id.

Hello,

I think the PoolID is an arbitrary identifier that only exists in the context of the activity using it (so you can have identical PoolID values in different activities without causing a problem).

PoolID groups child requestors as one: the system waits until all requestors with the same PoolID are finished before proceeding.

This means that when you reference a data page with parameters that can cause the data page to load data into multiple instances of itself on the clipboard, the system pauses until all data to these pages is loaded.