The (usually) three special zayin-like flourishes placed on some letters of the Torah, Tephillin, and Mezuzot that are thick on top and have a thin line extending downwards. The letter that receive the crowns are שעטנזגצ (see Menachot 29b) as well as the final ן and ץ (see Rashi there).
The Machzor Vitry (674–83) includes a copy of Sefer Tagin which addresses the tagin that appeared on the 12 stones which Moshe first set up in the Jordan River and that had been transferred later on to Gilgal (see Joshuah 4:9, 20) on which were inscribed the Torah text with the required tagin (see Ramban to Deuteronomy 27:8).
The point once again is that despite the fact that the trope, vowels, and crowns flesh-out the letters, add nuance and special import to them, enrich one’s reading of them, and despite the fact that each completes an action appropriate to it, they’re not essential, as the essential acts come about through the letters themselves as we indicated above.
(c) 2011 Rabbi Yaakov Feldman
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