A siyum () ("completion"), in Judaism, occasionally spelled siyyum, is the completion of any established unit of Torah study. The most common units are a single volume of the Talmud, or of Mishnah, but there are other units of learning that may lead to a siyum. The typical structure of a siyum event includes a conclusion of the study, reading of the Hadran text, kaddish, and a celebratory meal. The custom to make a siyum is first mentioned in the Talmud: "Abaye said: grant me my reward, for when I see a young Torah scholar who has completed a tractate, I make a celebration for the rabbis." Type of study The typical siyum is on a single book of Talmud, or on the entirety of the Mishna. This is due to the Talmud being an explanation of the Mishna, with each tractate of the Mishnah being relatively short, but the Talmudical version of it occupying an entire book. (A single published book of Mishnah typically covers many Tractates.) Talmud and Mishnah are organized in 6 sections (or "orders"), called sedarim in Hebrew. Sometimes, a siyum may be made on the completion of all the Mishnah of a seder, rather than the completion of all six at once. Conversely, a larger Talmudic siyum than usual may cover all Talmud in a seder, or even all of the Talmud comprising all six sedarim. Such a siyum is known as a Siyum HaShas, as HasShas an abbreviation of the Hebrew for "the six orders." Especially starting in the 20th century, other Judaic religious topics have been used to make a siyum, though often less formal than the standard Mishnah/Talmud siyum. One of the most common is the completion of the Mishna Berurah, a detailed work of the rules Jews practice each day, each Sabbath, and relating to each festival. Young schoolchildren sometimes make a siyum on completion of one of the five books of the Torah ("Books of Moses"). Shared study In many cases, the unit of study is not completed by any single person. Instead, the unit is split among participants, who complete one section. Jointly, the participants complete the whole unit. This is especially common for the completion of the entire six orders of the Mishnah after a person dies before the anniversary, and also frequently for one order of Mishnah within the month after their death. This format is also