Section 23(i) in The Bihar Civil Service (Executive Branch) and the Bihar Junior Civil Service (Recruitment) Rules, 1951
(i)The appointment to the Bihar Civil Service (Executive Branch) by promotion of any officer other than a Sub-Deputy Collector is not ordinarily desirable and no such appointments will be made save for reasons of an exceptional kind, and on the express recommendation of the Head of the Department in which the officer is serving and of the Board of Revenue.
