Payment Instrument and Doc Type

When we have payments made to vendors with certain payment instruments (V,E,R,P) it is creating a record with a doc type of PK. the user is wanting the dot type to be PT. Is there a way you can determine what doc type will be created for certain payment instruments? It looks like its automagically. We created a new payment instrument of X and it creates a doc type of PT and that is what they are looking for the V,E,R,P payment instruments to have.

I believe ‘Pre note code’ (P04012) causing to create PK records instead of PT. If Pre Note Code is checked then system will create PK record , if unchecked system will create PT record.This is irrespective of Payment Instrument.

Is this true? We have a PK created and its supplier doesn't have pre note code checked. What else could cause PK instead of PT?