color-management: Is transfer characteristics describing the OETF or EOTF

I remember we talked about this for a while but looking at the current protocol, it's not clear to me anymore.

We offloaded this entirely to CICP but we're not doing that anymore so we need to be more specific here. CICP says

either indicates the reference opto-electronic transfer characteristic function of the source picture as a function of a source input linear optical intensity input Lc with a nominal real-valued range of 0 to 1 or indicates the inverse of the reference electro-optical transfer characteristic function as a function of an output linear optical intensity Lo with a nominal real-valued range of 0 to 1

Which suggests they are OETFs and EOTF^-1.

TF with a pure gamma also exist and probably imply OETF=EOTF^-1.

Vulkan currently specifies its transfer characteristics as "to be displayed using an $NAME EOTF" which seems to clash with CICP.