# Identifiers (ECTAs)
An Identifier set or ECTA set is a combination of one or more identifying attributes which a service provider can specify per service in the Service Catalogue. This means that a service requires one or multiple ECTAs, or that a service can provide a preference for one ECTA with one or multiple alternative ECTAs.
Individual identifiers possible in ECTA sets are: KvK, RSIN, BSN (if allowed), PseudoID, and Pseudo. eIDASLegalIdentifier is currently not yet supported by the EU countries.
# User attributes
Here are all the possibilities and combinations per set:
- kvk (eH)
- rsin (eH)
- bsn (eH / eIDAS)
- kvk+rsin (eH)
- kvk+bsn (eH)
- pseudo (eIDAS)
- pseudoid (eIDAS)
- bsn+pseudoid (eIDAS)
- bsn+pseudo (eIDAS)
- bsn+pseudoid+pseudo (eIDAS)
- eidasLegalIdentifier (eIDAS)
# Examples
Example 1: Login with RSIN and KvK. These are the required identifiers for the service:
- Set 1: RSIN & KvK
Example 2: Login with RSIN, if RSIN is not available, then login with KvK:
- Set 1: RSIN
- Set 2: KvK
Example 3: Login with both RSIN and KvK, if that is not available, login with BSN and KvK:
- Set 1: RSIN & KvK
- Set 2: BSN & KvK
Example 4 eIDAS: Log in with BSN, if no BSN linked, log in with PseudoID:
- Set 1: BSN
- Set 2: PseudoID