code/modules/admin/data_input.dm

/datum/data_input_result	A datum holding the data the caller needs- the formatted output itself and the format the src selected (text, JSON, color, etc etc) Functionally a named tuple.
/datum/targetable/refpicker	Refpicker - click thing, get its ref. Tied to the data_input proc via a promise.
/proc/pick_ref	Gives the target mob a reference picker ability and returns the atom picked. Synchronous.