This is an inbuilt function function provided by PPWIZARD.
This function is used to retrieve a value previously stored away with the DataSave() function.
Note that this function has nothing to do with the #data command (or its data).
It is OK for the value not to exist, if this is the case the "default" value you specified will be returned. If you wish you can make the "default" value some sort of "invalid value" to detect what you consider to be an error.
The function takes 3 parameters as follows: