Used specifically for questions that are generally about Jewish holidays on which activity is heavily restricted (first and last days of Pesach, Shavuot, Rosh Hashana, Yom Kippur, first day(s) of Sukkot, and Shemini Ateret). But use [chagim-holidays] for questions about Jewish holidays in more generality; a specific-holiday tag for questions about any one holiday; and [shabbat] for questions that apply equally to Shabbat and holidays.
Used specifically for questions that are generally about Jewish holidays on which activity is restricted (first and last days of pesach, shavuot, rosh-hashanah-new-year, yom-kippur, first day(s) of sukkot, chol-hamoed shemini-atzeres and simchat-torah. Not for specific questions about any one of those holidays, though, as each has its own tag. And use chagim-holidays for questions about Jewish holidays in more generality, including purim, chanukah, lag-ba-omer; and shabbat for questions that apply equally to Shabbat and holidays.
More specific tags are shalosh-regalim, eruv-tavshilin, eruv-techumin, hallel, shehecheyanu, ochel-nefesh, hachana-prep-for-weekday, tractate-beitza birchas-kohanim and yizkor.
