Why some CPA firms named with the word ”(Practising)”?

There is no difference whether a CPA firm is calling themselves as CPA firm or CPA(Practising) Firm. The proprietor or partners are all holding a Practising Certificate issued by HKICPA.
The reason why there is a new wording CPA(Practising) because members of HKICPA are now calling CPA and members with practising certificate could call them CPA(Practising) after HKICPA has changed its name from the old name - Hong Kong Society of Accountants. This is the reason why the PC holders want to differentiate from the other ordinary members by calling themselves CPA(Practising) in order to give a clear designation to the general public.