Tag (Hebrew writing)
A tag (Aramaic: תג, plural tagin, תגין) is a decoration drawn over some Hebrew letters in the Jewish scrolls of Sifrei Torah, Tefillin, Mezuzot and the Five Megillot. The Hebrew name for this Scribal feature is kether (כתר). Both tag and kether mean "crown" in Aramaic and Hebrew respectively.
The letters Beth, Daleth, He, Heth, Yud and Quf have one tag (Mnemonic: BeDeQ-KhaYaH). The letters Gimel, Zayin, Tet, Nun, Ayin, Tzadi and Shin have 3 tags (Mnemonic: Sha´ATNeZ-GaTz). In kabbalistic thought, each tag has special significance and meaning. Some manuscripts feature embellished tagin on the top line of each column and some also on all occurrences of the Tetragrammaton other than those prefixed with a lamed (b. Seferot).
The tag embellishment is attributed Talmudically to Rabbi Akiva (b. Menahot 29b).