As we had previously a discussion on unusual symbols (on keyboards), here is another one, namely Unicode U+237B, RIGHT ANGLE WITH DOWNWARDS ZIGZAG ARROW, also known by its ISO TR9573 entity name “Angzarr”. Apparently, nobody knows what it is meant to mean or to represent.
Recently, I stumbled over a Youtube video on this, and there are some interesting suggestions in the comments. Namely, it may be a symbol to indicate a grounded high voltage path (used in railway operations?), but – even if this is the case – it’s unclear, if this is a genuine use or rather an adopted one, because there was this unused symbol. A comment rather specifically states that it was found in pre WWII Sears drawings. And, besides that, there is quite a number of cases of adopted use, after it became canonized in ISO TR9573-13 and in the ISO SGML entity set.
(E.g., SPSS used it for an unplotable value.)
However, we do know how it made its way into the Unicode set, compare this Stackexchange thread and this webpage: https://ionathan.ch/2022/04/09/angzarr.html
Here, Barbara Beeton (from the STIX project collecting the information for that table) provides the following information,
I had no idea what it meant or was used for, thus assigned it a “descriptive name” when collating the symbols for the STIX project. (I still have no idea, nor can supply an example of the symbol in use.) […] it is the case that ISO 9573-13 existed long before either AFII or the STIX project were formed. […] I once asked Charles Goldfarb what the source of these entities was, but remember that he didn’t have a definitive answer.
Still, there are questions. Especially regarding where it shows up in Unicode.
First, there’s a large block of APL characters, ending in,
⍹ U+2379, APL FUNCTIONAL SYMBOL OMEGA UNDERBAR
⍺ U+237A, APL FUNCTIONAL SYMBOL ALPHA
This is followed by a block of control pictures for communication, with the Angzarr as the second character,
⍻ U+237B, NOT CHECK MARK (Negative Acknowledge, ISO 2047)
⍼ U+237C, RIGHT ANGLE WITH DOWNWARDS ZIGZAG ARROW (???)
⍽ U+237D, SHOULDERED OPEN BOX (keyboard symbol for No Break Space)
⍾ U+237E, BELL SYMBOL (ISO 2047)
⍿ U+237F, VERTICAL LINE WITH MIDDLE DOT (End of Medium, ISO 2047)
Then, there’s a block of keyboard symbols from ISO 9995-7,
followed by a block of electrotechnical symbols from IR 181,
the “oh crap, we forgot an APL symbol” U+2395 (APL FUNCTIONAL SYMBOL QUAD),
and another block of keyboard symbols from ISO 9995-7 (“decimal separator and screen navigation may be useful, as well”).
(from Unicode U2300, https://unicode.org/charts/PDF/U2300.pdf)
This somewhat suggests a use as a communications symbol. So, even if this was not its original meaning, does somebody know about an application in this field?