wait STIX is part of AMS. STIX references the ISO standard for the character but the ISO standard lists AMS-A as the source so I no longer know anymore
The only LaTeX package that has the symbol is stix https://www.ctan.org/pkg/stix which was created in 2001 and calls it \rangledownzigzagarrow and I couldn't find it in amsmath or amstex so I have a feeling that even though the character is under ISO AMS-A I don't think it's actually from the AMS
See the problem is that the ISO standards might list the characters but they don't give explanations for what they're supposed to mean, AND ISO isn't very... open so they don't give things like proposal documents and meeting minutes like Unicode does, so it's hard to track down something that suddenly appears in an ISO standard They're basically dead ends
Ok I was wrong. There are publicly available minutes and proposal comments and whatnot, like this https://www.jtc1sc34.org/repository/0601.htm but it seems rather hard to search for them unless you have the write keywords to google...
"(JTC 1 June 1998 Resolution 19 Disbandment of JTC 1/WG 4 and Establishment of a New Subcommittee 34) This new SC will operate in the Technical Direction - Document Description Languages - with the following title and scope:"
oh it used to be a different working group in charge of this I guess
okay so ISO says the subcommittee in charge of this tech report is ISO/IEC JTC 1/SC 34 but I'm looking at their documents and they only go back to 1998 when the original TR was published in 1991 what gives