3GPP 23.501 v20.2.0 — the document's own text

6.2.5.1 Support for CAPIF

Taught in 4. What each network function does (The 5G system architecture, in depth), 2. Who does what in the core (The 5G system architecture, overview).

When an NEF is used for external exposure, the CAPIF may be supported. When CAPIF is supported, an NEF that is used for external exposure supports the CAPIF API provider domain functions. The CAPIF and associated API provider domain functions are specified in TS 23.222 [64].