(Vol. XXIV, 1914, p. 153)
If this question refers to the preceding, I would suggest that the mourners stand at all recitals of the Kaddish for the dead, for whom mourning is a legal duty (viz., relatives in the first degree). If this question be general, I refer to Yoreh De-a, Hil. Avelut, where certain distinctions are set forth as the established din and minhag.
S.B. Freehof, "Kaddish for First Wife," Reform Responsa, pp. 162ff; "Kaddish and Yahrzeit for a Child," ibid., pp. 165ff; "Kaddish for Apostates and Gentiles," Recent Reform Responsa, pp. 132ff; "Some Kaddish Customs," Current Reform Responsa, pp. 178ff; "Kaddish and the Three Steps Backward," Recent Reform Responsa, pp. 217ff; "Gentile Visitors and the Kaddish," Modern Reform Responsa, pp. 62ff; "Kaddish When Worshiping Alone," Recent Reform Responsa, pp. 14ff.