It is an Ashkenazi custom to recite Yizkor on Shavuos immediately after the completion of the Haftorah. In the Diaspora, the custom is to recite Yizkor on the second day of Shavuos, after the Torah reading.
Aliyah: It is not the custom to be particular to receive an Aliyah on the day of Yizkor.
Mention the name of the mother of the deceased? The name of deceased and his or her mother is mentioned by Yizkor.
Mentioning the Rabbeim: It is customary amongst Chassidim to mention the name of the Rabbeim that they were Chassidim of in Yizkor. This has an effect on the Chassid saying it.
Mentioning men and women separately: Men and women are to be mentioned separately in Yizkor.
No Minyan: Yizkor may be recited even if a Minyan is not present.
Charity: One is to pledge charity during Yizkor on behalf of the soul of the deceased.
When to light: The Yizkor candle is to be lit before Yom Tov. One who did not do so before Yom Tov may light it on Yom Tov inside an active Shul, in the room where the prayer takes place. However one may not light the candle in one’s home on Yom Tov. However there are opinions who allow lighting it even at home. See Chapter 2 Halacha 9!
Yizkor during the first year of Aveilus:
When Yizkor is taking place during the first year of Aveilus, the mourner remains in Shul for Yizkor, although he does not recite anything while there. He is not to recite the Yizkor even quietly.
After 12 months in a leap year: One who is still prior to the first Yartzite, but is past 12 months of mourning, is to remain in Shul and recite Yizkor regularly.
If the mourner needs to say Yizkor for another parent who is past the 1st year: If one is within the year of one parent and past the year for another parent, then only the parent’s name that is past the year is to be mentioned in Yizkor.
 The custom of Yizkor on Yom Tov is first mentioned in 621:14 regarding Yom Kippur; Regarding other Yomim Tovim: Nitei Gavriel Aveilus 2 78:4 that so is custom even though there is no known source for this in Poskim [See there footnote 11]; The following Poskim mention the custom of reciting Yizkor on Yom Tov: P”M 547 A”A 2; Kav Hayashar 86; Yalkut Hagershoni 621:2; Betzel Hachochmah 4:119
 Sefaradi communities do not recite Yizkar.
 Shaareiy Efraim 10:32
 The reason: This is due to Ayin Hara.
 Igros Kodesh 3:220 [printed in Shulchan Menachem 2:250]
 Igros Kodesh 3:220 [printed in Shulchan Menachem 2:251]; Hamelech Bemisibo 1:309; Otzer Minhagei Chabad Yom Kippur p. 222
 This is learned from a play on words “Eitz Chaim Hi Lamachazikim Ba”, that one is to hold on to the Eitz Chaim for long life. [Hamelech Bemisibo ibid]
 Kaf Hachaim 284:37 based on Zohar; Siddur Torah Or; Hamelech Bemisibo 2:166; Igros Kodesh Miluim, [printed in Shulchan Menachem 2:251]; Mishnas Sachir 2:233 that so is the custom in Ungarin; See Divrei Torah Munkatch 2:90; Nitei Gavriel 79:14 in name of Poskim
Other customs: Some are accustomed to mention the name of the father by Yizkor. [See Zohar brought in Hamelech Bemisibo ibid; Mishnas Sachir 2:233 that so is the custom in Poland; Nitei Gavriel 79:14 in name of Poskim and that so is the custom]
 Toras Menachem 46:343 [printed in Shulchan Menachem 2:252]
 Nitei Gavriel Aveilus 79:13
 Gesher Hachaim 31:6
 See Admur 621:14
 Hamelech Bemisibo 1:321 [printed in Shulchan Menachem 2:250]; However in Luach Kolel Chabad it says to light it.
 Heard from Rav Leibal Groner
 See Admur 514:14; Biur Halacha 514 “Ner”; Piskeiy Teshuvos 514:14
 Biur Halacha ibid; Piskeiy Teshuvos ibid footnote 70; See SSH”K 13 footnote 27
 Biur Halacha ibid; Piskeiy Teshuvos ibid
The reason: As one may light any candle in Shul as it is considered a Neir Shel Mitzvah. [514:14]
Other Opinions: Some Poskim rule one may never light a Yartzite candle on Yom Tov, even in Shul. [Daas Torah 514 in name of Imrei Eish] Some rule one may only do so through a gentile. [Kitzur SHU”A 98:1]
 Piskeiy Teshuvos ibid
The reason: As it does not add any light to the house even at night being that we have electricity. Thus, it may not be lit as it is considered a light that serves no purpose which is forbidden to be lit on Yom Tov. [514:13]
 Biur Halacha 514 “Neir”
 Initially one is to light it near one’s dining room table, thus giving it a use. However, if this is not possible, then one may light it in any area as it is considered a Ner Shel Mitzvah. [ibid]
 Sefer Haminhagim p. 125 [English]
 So is the final ruling of the Rebbe in Sefer Haminhagim ibid, unlike Igros Kodesh 3:7 [printed Shulchan Menachem 5:308] in which the Rebbe directs to recite the Yizkor silently
 Directive of Rebbe Rashab to Rav Yaakov Landa brought in Otzer Minhagei Chabad Yom Kippur 195