please allow me to introduce myself
Archaic formal greeting used historically among yakuza, street vendors, gamblers, and similar groups. Not used in modern standard Japanese.
I've heard the greeting 'お控えなすって' in old yakuza movies.
Derived from お控えなさる (a respectful form of 控える, 'to wait' or 'to be in attendance'), with the contracted なすって. The exact historical development is uncertain, but it likely served as a formal self-introduction in certain subcultures.