ICAO PPL is used to describe a PPL issued in acccordance with ICAO Annex 1.
Examples include JAA PPL, UK PPL isued prior to JAA changeover French PPL, Irish PPL and so on.
Example excluded is the UK NPPL.
Holders of an ICAO PPL can exercise the licence privileges on aircraft of the country where the licence is issued worldwide without for the most part having to ask permission.
An NPPL holder flying say a C172 however is limited to UK airspace.
One will also hear pilots talking about ICAO ratings.
Examples of ICAO ratings are SEP (LAND), MEP(LAND) and the IR.
Example of a National or NON-ICAO reating is the UK IMC which is valid only in UK airspace.
When trying to gain a validation or licence in another country, having an ICAO licence helps. A non-ICAO licence can cause problems unless the training is to a certain certified standard that the authorities will accept it.
Regards,
DFC