RPCs are defined as currently non-localized chat messages to be interpreted by the addon or other tools e.g. WeakAuras.

I need to be able to send RPCs in any locale with item links for that locale.
I need to be able to send RPCs in a locale other than my client's locale.
I need to be able to translate RPCs from any locale to my locale for display purposes in the addon.
I need to be able to match RPCs in any locale for addon handling such as ignoring messages.

This is a breaking change and requires a major version increment.

This addon can be used to translate item links to a selected locale
https://legacy.curseforge.com/wow/addons/itemnamedb

Example of translating a chat message to a different language (this is on recv, not on send, so here the actual channel text is English as typed)