Section 5(2)(b) in National Housing Bank (Officers') Service Regulations, 1997
(b)If an Officer who is in receipt of Professional Qualification Allowance is promoted to next higher scale, he shall, subject to Government guidelines, if any, be granted, on fitment into such higher scale, additional increment(s) for passing CAIIB to the extent increments are available in the scale and if no increments are available in the scale or only one increment is available in the scale, the officer shall be eligible for Professional Qualification Allowance in lieu of increment(s).