Meaning of the term "profession of accountancy" under section 44aa

Hello Ca club members and experts

If a CA provides only tax services or only audit services, will we still say that he is carrying on the profession of accountancy? Will he have to keep and maintain books of accounts under section 44AA and be liable to the provisions of 44ADA even though he does not provide accountancy services? Can you provide a legal reference that clearly explains the meaning of the term "Profession of Acccountancy"? This term has been used in Section 44AA but I couldn't find its exact meaning.

Thank you

Regards