Teth is one of seven Hebrew letters, recalled by the mnemonic shatnez getz, that Jewish law requires a scribe to crown with three small decorative strokes called tagin in a Torah scroll, tefillin or mezuzah, a rule fixed in the Talmud at Menachot 29b. Teth is drawn as a nearly closed curl, open only at the very top, and a widely cited homiletic teaching connects that shape to the letter's numerical value of nine and to the word tov, good, which some traditional commentary treats as first appearing in the Torah's account of creation in close association with the letter; readers in this tradition take the almost total enclosure of Teth's shape as a figure for goodness that is present but hidden, visible only once the narrow opening at the top is found.
Teth also marks a boundary in the Hebrew numbering of days and months, since single Hebrew letters serving as ordinal numbers run cleanly from Aleph through Teth for one through nine before the tens begin with Yod, making Teth the last of the units and, in that narrow sense, the letter that completes the first rank of the traditional Hebrew numeral sequence discussed at greater length elsewhere in this atlas. Because the seven crowned letters discussed elsewhere in this atlas are memorised as a fixed set rather than derived from any shared visual feature, a sofer must simply know that Teth belongs among them, taking three tagin wherever it appears in a Torah scroll, tefillin or mezuzah.