Chapter 26: 7-9
The Mourners Kaddish
7. When there are two mourners with equal privileges, lots should be cast
between them. The one who wins is entitled to recite [the Kaddish in] the
evening service. Accordingly, the other is entitled to recite one Kaddish
without casting lots in the morning service, and lots should be cast for
the third Kaddish.
Similarly, if there are many mourners, lost are cast. Whoever, won once is
excluded from the future castings, until all have recited [Kaddish at least
once.]
8. A resident mourner has precedence over a guest (if the latter has passed
the seven days of mourning). When the yahrzeits of a resident and a guest
coincide, the guest is not granted [a single Kaddish].
Should a resident be observing the thirty days of mourning or be in the
year of mourning and a guest be commemorating a yahrzeit, the guest is
entitled to one Kaddish.
[This applies even if a resident commemorating a yahrzeit is also present;]
the guest may still recite one Kaddish. The resident commemorating a
yahrzeit cannot tell the guest, my rights supersede yours," for the guest
can tell the resident: "I am not taking the privilege from you, but from
the person observing the thirty days of mourning." Thus, the resident
commemorating the yahrzeit should recite the first Kaddish; the guest, the
second; and the person observing the thirty days of mourning, the third.
9. A guest observing the thirty days of mourning and resident within the
year of mourning are considered equal.