In the "Performing Rights Organization (PRO)" field at track level, please enter the collective management society or entity where this track's authorship is registered (e.g., SGAE, SACM, ASCAP, BMI, SADAIC).
If the track isn't registered yet, leave this field blank.
If it's a cover, this field refers to the original songwriter's entity, not yours as the performer.
If you don't know it, leave it blank.
If there is more than one PRO, separate them with a comma."
CISAC list (collecting societies) https://members.cisac.org/
This field is not mandatory.