What is a CType?
A claim type (CType for short) is is the standardized structure for credentials on KILT. You can think of it as the data model for your claim.
It contains fields that are filled out by the claimer indicating the information that needs to be attested. A CType (and subsequently when attested, the credential) may contain several “attributes”, such as full name, date of birth, access level and id number.
A CType ensures that a claim contains all the attributes needed. For example, a driver's license would need to contain a name, date of birth, and the type of vehicle that can be driven by the claimer. The CType is especially important since a verifier would request attestations for a specific CType (e.g., the traffic police wants to see your driver's license and not your gym membership).
For more information on CTypes, see our in depth CType documentation.