The Torah portion of Ki Savo:
In the sixth Aliyah the Torah portion discussing the curses is read.
Avoiding an interval by the curses: The custom is not to make an interval of Aliyos by the curses of Ki Savo. One is to read from at least three verses prior to the curses and conclude at least three verses after the curses.
Not to call up by name: The custom is to not call anyone by name for the Aliyah of the curses, which is the 6th Aliyah, and rather whoever desires goes up for the Aliyah ]without being called[. [Many are accustomed to designate this Aliyah to a specific person and in such a case] one is to avoid going up for this Aliyah in place of the person that it is set to be given to. [Many are accustomed that the Baal Korei himself is designated to receive this Aliyah. Practically, this is the Chabad custom. The Baal Korei is not called up by name and hence begins the blessings on his own. The Baal Korei may receive a Mi Shebeirach with his name after the Aliyah.]
Reading the curses in a low voice: The custom is for the reader to lower his voice upon reading the curses. He raises his voice again only by the words “Eilu Divrei Habris” in the end of Shishi.
What is one to do if the Baal Korei is a Kohen?
As brought above, many are accustomed [and so is the Chabad custom] that the Baal Korei receives the Aliyah of the curses. If the Baal Korei is a Kohen, then some Poskim rule he should read seven Aliyos prior to the curses and then go up and read the curses as an eighth Aliyah. However, it is not allowed for the Kohen to go up for the curses if it is still the 6th or seventh Aliyah. [Practically, however, according to the Chabad custom the Baal Korei may not add or change the Aliyos. Therefore, the Kohen is not to go up and rather another person should do so without his name being called.]
The Chassidus of this Shabbos was heard with completely different concentration. On Friday night of Shabbos Selichos, Chassidim would diminish their amount of sleep as they were unable to sleep. A person did not find his place. They would go to Mikveh prior to daytime. In the Mikveh they would meet many others hurrying on their way. It was recognizable that this Shabbos was different than every other Shabbos. In one’s mind passes the thought “To you Hashem is righteousness and to us is the face of shame”. One would immerse with a broken heart and question himself whether this is an immersion of true repentance or is he immersing with the rodent in his hand. When they would pass Binyamin’s Shtible they would hear the congregation saying Tehillim. The Tehillim of that Shabbos was also different then all the other Shabbasim.
It is customary to hold a Chassidic gathering on Motzei Shabbos in the hours prior to Selichos.
On the Shabbosim which are in approximation to Rosh Hashanah, two chapters of Pirkei Avos are read, in order to complete the cycle prior to Rosh Hashanah.
Reciting “Kol Yisrael…” prior to each chapter and “Rebbe Chanania Ben Akashyia…” at the end of each chapter: One is to recite the Mishnaic saying of “Kol Yisrael…” prior to beginning the chapter of Pirkei Avos. At the conclusion of the chapter one is to recite the teaching of “Rebbe Chanania Ben Akashyia.” [On the Shabbosim which are in approximation to Rosh Hashanah, in which two chapters of Pirkei Avos are read, some write one is to read the above opening and closing statements before and after each individual chapter. Others write it is only to be said once; the opening statement at the beginning of the first chapter and the concluding statement after concluding the second chapter. Others write that by the first four chapters that are said together [1-2 and 3-4], one reads the opening statement at the beginning of the first chapter and the concluding statement after concluding the second chapter. However, by the last two chapters [5-6] one reads the opening and closing statement after both the first and second chapter.]
 One does not make an interval in the reading of the curses in Bechukosaiy, and reads from three verses prior and three verses after the curses. However, by the curses of Ki Savo one may make an interval, [as they were said by Moshe in the singular tense and hence are not as severe-M”B 428:18]. Nevertheless, the custom is not to make an interval even by the curses of Ki Savo. [Michaber ibid]
 Michaber ibid
 M”A 428:8
 Rama 428:6
 The reason: As we suspect that if one is called by name he may not want to go up for the Aliyah and will despise the curses [as well as doing so shortens one’s life-Brachos 55a]. Hence, one is to arrange in advance who is to receive this Aliyah. [Levush 428; M”B 428:19; Biur Halacha “Beshmo”; Kaf Hachaim 428:40]
 M”A 428:8 in name of Mahril “The Mahril despised those that went up for the Aliyah as it is only to be given to the Shamash who is hired for this purpose.”
Will something evil befall one who receives this Aliyah? Those who go up for this Aliyah suspect that something evil will befall them. However, certainly if one is doing so out of respect for the Torah, nothing evil will befall him. [M”B 428:17] The Sefer Chassidim 766 states that in previous generations they would call an ignoramus for this Aliyah in order so the evil does not befall a Torah scholar. Nevertheless, if a Torah scholar was called up he is not to refrain from reading it. [brought in Kaf Hachaim 428:34] The Kneses Hagedola states that no evil will befall anyone, as one has no intent to recite curses at all. [brought in Kaf Hachaim ibid] In Shaar Hakavanos p. 73 and Peri Eitz Chaim it states that the Arizal went up to the Torah for this Aliyah and read the Torah as is the Sephardic custom.
 M”B 428:17 “This is a proper custom”; Kaf Hachaim 282:8; 428:35 “So is the custom today”; Darkei Chaim Veshalom 203
 Hayom Yom p. 88; Sefer Haminhagim p. 31; See Otzer Minhagei Chabad p. 19
 Hiskashrus 840
 Peri Chadash 428:7; M”A 428:8 in name of Kneses Hagedola regarding Parshas Haeigel; Kaf Hachaim 428:38; Hiskashrus 840. In Shaar Hakavanos and Peri Eitz Chaim it states that the Arizal went up to the Torah for this Aliyah and read it in a loud voice.
 M”B 428:17
 See Rama 135:10
 Tzemach Tzedek 35 [Custom of Alter Rebbe who was the Baal Korei]; Sefer Haminhagim p. 31; Igros Kodesh 3:31
 Likkutei Deburim Vol 1 page 151-158
 Siddur; Admur in 54:4
The reason: The reason we conclude with these verses is because it is customary to recite Kaddish after Pirkei Avos, and we do not recite Kaddish unless we read a teaching that contains a verse or an expoundation of a verse. [Admur 54:4]
 Otzer Minhagei Chabad p. 246 based on Sichas Netzavim Vayeilech 1987
Background: The Rebbe in Sichas Parshas Seitzei 1981 plainly mentioned that the custom is to say it only once. However, in later years, the Rebbe publically debated whether it should be said once or twice. [See Hisvadyus 1985 5:2887; Hisvadyus 1987 4:352; Hisvadyus 1989 4:279; Sefer Hasichos 1990 2:681; Sefer Hasichos 1991 2:797] This led to a variety of opinions on this matter.
 Hiskashrus 946 based on Sichas Parshas Seitzei 1981
 Siddur Tehillas Hashem Kehos Eretz Yisrael based on Hisvadyus 1990 4 page 259 footnote 104 and Hisvadyus 1987 4 page 400