Must the lower Yud of the Alef (and similarly the upper Yud and other letter components) be present for the letter to be valid, and does the right vs. left spine of a Yud have different legal status?

Must a scribe write STaM (Sifrei Torah, Tefillin, Mezuzot) in 'ketivah tamah' (the traditional calligraphic script style)?

4 opinions

Does a letter's shape becoming defective after writing (through a hole, tear, or smudge) invalidate STaM?

1 opinions

Does partial resemblance of a letter to another letter (only part of the letter resembles a different letter) invalidate STaM?

3 opinions

Must each letter in STaM be a single unified entity (guf echad), and what does this require for letters with detached components (such as the Yud of an Alef, the Yuds of Shin and Ayin, the Yud behind a Tzadi)?

5 opinions

What is the minimum gap required between the suspended leg of the Heh (and Kuf) and the roof of the letter?

2 opinions

Is the leg (regel) of Heh or Kuf touching the roof (gag) a post-writing defect or does it only invalidate at the time of writing?

1 opinions

Must a scribe add tagin (crowns) to the letters of SHATNEZ GETZ in STaM, and does omitting them invalidate the document?

5 opinions

Are there additional tagin beyond SHATNEZ GETZ that scribes add to STaM, and do they invalidate if added improperly?

2 opinions