A survivor election under subsection (j) or (k) of section 8339, or under section 8416, 8417, or 8420 of title 5, United States Code, which is otherwise required to be in writing may be effected in such form as the Director prescribes under Sec. 850.104. [72 FR 73576, Dec. 28, 2007, as amended at 78 FR 68983, Nov. 18, 2013]