The fact you don't approve of the term does not mean it causes mass confusion to those people wishing to undertake electrical installation work (diy or for payment).
The Approved Document states that a 'Registered Competent Person' is a member of a self-certifying scheme, for notification purposes. If the OP wants to self-certify his jobs, he has to join a scheme.
Para 3.10 then indicates that an installer who can prove their 'competence' (in the true sense) to I&T may be able to pay a lower LABC charge, subject to the LABC accepting their qualifications.
The Approved Document states that a 'Registered Competent Person' is a member of a self-certifying scheme, for notification purposes. If the OP wants to self-certify his jobs, he has to join a scheme.
Para 3.10 then indicates that an installer who can prove their 'competence' (in the true sense) to I&T may be able to pay a lower LABC charge, subject to the LABC accepting their qualifications.