Section 17(2)(a) in Delhi Private Security Agencies (Regulation) Rules, 2009
(a)For the Guard/Supervisor. -(i)to put an arm badge for the guard distinguishing it from other agency;(ii)to put a shoulder or chest badge to indicate guard's position in the organization;(iii)to put a whistle attached to the whistle cord and to be kept in the left pocket of the shirt;(iv)rubber sole shoes with eyelet and laces;(v)a headgear having the distinguishing mark of the private security agency;(vi)every guard shall carry a notebook and a writing instrument with him.