U+237C ⍼ is (also) S9576 ⍼

Part 1: U+237C ⍼ RIGHT ANGLE WITH DOWNWARDS ZIGZAG ARROW
Part 2: update: U+237C ⍼ angzarr;
Part 3: Monotype Mathematical Sorts
This is part 4.
Many thanks to Sallie Morris at the Science Museum Group, Claire Welford-Elkin at St Bride Library, and Brian Corrigan for their help.
This update was originally posted on cohost.

Monotype Mathematical Sorts

Part 1: U+237C ⍼ RIGHT ANGLE WITH DOWNWARDS ZIGZAG ARROW
Part 2: update: U+237C ⍼ angzarr;
This is part 3.
Part 4: U+237C ⍼ is (also) S9576 ⍼
Many thanks to Alicia Chilcott and Sophie Hawkey-Edwards at St Bride for their help.

UPDATE: U+237C ⍼ ⍼

Part 1: U+237C ⍼ RIGHT ANGLE WITH DOWNWARDS ZIGZAG ARROW
This is part 2.
Part 3: Monotype Mathematical Sorts
Part 4: U+237C ⍼ is (also) S9576 ⍼
Many thanks to Barbara Beeton, James David Mason, Anders Berglund, David Bolton, Andy Whyte, Claire Welford-Elkin, and Bob Richardson.

U+237C ⍼ RIGHT ANGLE WITH DOWNWARDS ZIGZAG ARROW

This is part 1.
Part 2: update: U+237C ⍼ angzarr;
Part 3: Monotype Mathematical Sorts
Part 4: U+237C ⍼ is (also) S9576 ⍼

Known as right angle with downwards zigzag arrow, angle with down zig-zag arrow, \rangledownzigzagarrow, and ⍼, no one knows what ⍼ is meant to represent or where it originated from. Section 22.7 Technical Symbols from the Unicode Standard on the Miscellaneous Technical block doesn’t say anything about it.

U+23BE..U+23CC DENTISTRY NOTATION SYMBOLS

The Unicode Standard has its fair share of mysterious and sometimes unexplained characters. The story of the Farsi symbol (U+262B ☫ farsi symbol) is one of the more well-known ones. Many blocks, especially the “miscellaneous” blocks, have smatterings of rather arbitrary character sets grouped together only by history. One such block is Miscellaneous Technical, which contains completely unrelated groups of characters, including keyboard symbols, APL symbols, electrotechnical symbols, UI symbols, drafting symbols, and of particular interest in this blog post, dentistry notation symbols. Here they are, all 15 of them:

⎾⎿⏀⏁⏂⏃⏄⏅⏆⏇⏈⏉⏊⏋⏌

The first two and last two are part of Palmer notation for denoting human teeth by their position. What are the rest for?