14 
Right to § 21. Any subscribing employee may designate a per- 
a 0 son or persons, absolutely or contingently, as his or her 
Y beneficiary or beneficiaries for the purposes specified in 
these rules. Any such designation may be revoked 
at any time by the subscriber and a new beneficiary 
may be substituted. But no such designation or revoca- 
tion thereof shall be valid, unless made by a written in- 
strument, in a form approved by the Pension Board, 
and filed with the Pension Board during the lifetime 
of the subscriber. 
Benefi- § 22. The right of a beneficiary designated pursuant 
ciary’s to these rules to receive a gratuity shall not be assign- 
ee i sra- able or bequeathable, and any attempted assignment 
aeons or bequest thereof shall be void and shall be disre- 
garded by the Corporation and the Pension Board. 
Computing § 23. For the purpose of ascertaining the term of 
service past service of any person who shall be in the perma- 
nent service of the Corporation when these rules take 
effect and who shall become a subscribing employee, 
the entire period prior to that date during which such 
person received pay from the Corporation, but after, 
in the case of a male employee, he had attained the age 
of twenty-one years, or, of a female, the age of eighteen 
years, shall be taken into consideration. As applied 
to the period after these rules take effect, the words 
continuous service, or other similar words, as used in 
these rules, shall be construed as meaning that period 
for which, after becoming a subscriber, and after the 
age of twenty-one years in the case of males, and of 
eighteen years in the case of females, a subscribing 
employee shall have remained in the service of the 
Corporation, and shall have paid his or her contribu- 
tions to said Pension Fund without a greater continu- 
ous break in his or her service than one year, and 
provided that, upon returning to the service after any 
such break in the continuity thereof, the said subscriber 
