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Fasts and Eulogies: 
It is forbidden to fast or deliver eulogies on the 14th or 15th of Adar. This applies in all places and to all Jews whether they are inhabitants of a city that is celebrating Purim on the 14th or a city that is celebrating Purim on the 15th.
Is a Chasan and Kallah to fast on Purim if it is the day of their wedding?
May a eulogy be given on Purim on behalf of a Torah scholar that passed away?
May one fast or give a eulogy on Sunday of Purim Meshulash?
A Chasan and Kallah: A Chasan and Kallah are not to fast on Sunday of Purim Meshulash.
May one cry out of mourning on Purim?
No. One may not cry out of mourning of a person who passed away a number of days before Purim.
May one visit a cemetery Purim?
An Avel at the conclusion of Shiva: An Avel may visit the grave his relative at the end of Shiva. Those people which are not Aveilim are not to participate in the visitation. [Some Poskim however write that even an Avel at the end of Shiva should not visit the cemetery.]
May one say Hashkava or Tziduk Hadin on Purim?
 Rama 695/2
 M”A 695/4
 Nimukei Orach Chaim 420; To note that Rav Moshe Feinstein was eulogized on Purim 1986; See Piskeiy Teshuvos 547/1; 696/4
 Mahraiy Algazi 11; Piskeiy Teshuvos 696/4
 Beis Yehuda 24; Birkeiy Yosef 696/8; Shaareiy Teshuvah 696/4; Kaf Hachaim 696/18 and 20
 M”A 696/5 in name of Mahrash Halevi 13; Kneses Hagedola 696; Olas Shabbos 696/2; Elya Raba 696/3; Kaf Hachaim 696/17; M”B 696/8
 Gesher Hachaim 1 p. 259
 See Piskeiy Teshuvos 696 footnote 16 which explains the ruling of the M”A 696/5 to forbid going to a grave site on Erev Purim to only be referring to the women who lament over the grave, however the Avel may visit he grave at the end of Shiva.
 Michaber Yoreh Deah 401/6; Kneses Hagedola 696 brought in M”A 696/5
 Rama Yoreh Deah 401/6; Levush brought in M”A 696/10; M”B 696/16