4. Maintenance of registers. - Every employer shall prepare and maintain the following registers, namely:

(a) A register showing the computation of the allocable surplus referred to in Cl. (4) of Sec.2 in Form A ;

(b) A register showing the set-on and set-off of the allocable surplus, under Sec.15, in Form B ;

(c) A register showing the details of the amount of bonus due to each of the employees, the deductions under Secs.17 and 18 and the amount actually disbursed, in Form C.