Deets are user's detailed information stored privately within one's profile. Information includes First Name, Last Name, Country, Selfie photo, Postal, and Date of Birth.
These information went through a 3rd party verifier upon user's submission of a valid legal document. All information stored on deets remain private unless user shared them 'manually' to others.
You will see a user to have a "shield w/ check" (verified) icon on his/her profile when that user has deets stored on his/her account.
Deets can be swapped between users. But only verified users can request for swapping of deets.