In this Part—
“complainant”, in relation to a complaint, means the person who makes the complaint;
“relevant authorising body”, in relation to a person, means—
an approved regulator by which the person is authorised to carry on an activity which is a reserved legal activity, or
where the person is authorised to carry on such an activity by the Board in its capacity as a licensing authority, the Board;
“respondent”, in relation to a complaint, is to be construed in accordance with section 125 (except that, where scheme rules of the kind mentioned in section 133(3)(c) have effect, references to the “respondent” include a person treated as a co-respondent under those rules).