What is the usual identifier we use in the code for IdP and SP?

[Rod Widdowson]

Odd question this.

I need to add the SP and the IdP entityIDs to the SubjectC14NContext (some
of the NameID Decoding require it).  Up to now I have been inside the
attribute resolving or attribute filtering space and so it was usual to
refer do this by using 'issuer' and 'recipient' as prefixes.  But in this
context those terms do not make sense.

What is the usual prefix that people use ?  RP seems deprecated and
confusing.  Is SP and IdP (or rather sp and idp) sufficient?   I know that
V2 tried quite hard to avoid those term because of the possibility of flows
where and IdP could be acting more like an SP and vice versa, but it seems
needless to tie oneself in knots over it.

Rod