What do the respective “approval” status details mean?

Incomplete: The soundfile was uploaded but not all required details have been entered. (Mandatory details such as title, author, work number, details on commissioned music have not been entered and are yet to be completed by you. All other details are optional.)

Ready for approval/release: All mandatory details have been entered and all details are complete. You can now approve and release the files.

Approved/released: You have approved the use and the data is now ready for the audio fingerprint service providers.