Unless excused by the Examiner an eligible may be removed from a register if he or she is unavailable for appointment. Eligibles may be excused from availability as follows:
(1) An eligible in military service shall be granted a deferment of certification for a period not to exceed ninety (90) calendar days (or a longer time period if required by State or Federal law) upon request of the eligible.
(2) An eligible who is on an authorized leave of absence from City employment may be granted a deferment of certification during the leave period, or he or she may be certified for appointment if the leave is expected to end within a reasonable time period, as determined by the Examiner.
(3) The Examiner may grant deferral of certification if requested by an eligible who shows good cause for the deferral. The deferral may be granted for a specific time period or until certain conditions have been met.