Jeff Rearick proposed this definition in an email.
PDL: IEEE 1687 Procedural Description Language which is the language for writing tests for modules
Michele commented: " ...tests for modules in the CSU retargeting Domain".
This is really a key point for me: even though the iApply frame can theoretically express any combination of Capture, Shift and Update, the behaviour of the PDL code is tied to CSU and is not portable. I should find the time to make some examples on it, IMHO it also impact 1687.2.