There is provided mechanisms for enabling selection of service-providing NFs in a 3GPP communication network. A method is performed by an NRF. The method comprises obtaining one register request from each of the service-providing NFs. Each registration request comprises an NF profile. Each NF profile comprises a security setting attribute. The method comprises storing the NF profiles of the service-providing NFs. The method comprises obtaining a discovery request from a service-requesting NF. The request indicates an NF type. The method comprises providing a discovery response to the service-requesting NF. The discovery response comprises the NF profile of at least one of the service-providing NFs of the NF type, thereby enabling selection of the service-providing NFs. The security setting attribute may pertain to support for mutual TLS and/or for use of OAuth-2 based authorization.