Hello everyone. Since 2010, I have maintained a reasonably complete list of annotated codes for historical and modern natural history collections associated with lost and extant specimens of fossil and Recent fishes, amphibians and reptiles.
The list currently includes 3784 codes anchored to about 2033 collections or institutions in 150 countries. A slightly dated version of the list is available here: https://asih.org/standard-symbolic-codes/about-symbolic-codes. An updated list was submitted for print publication in Copeia.
This list was generated by combing the fish and herp literature (1769 publications) for citations of codes and with help from fish/herp taxonomists and collections staff around the world.
Anyway, I can attest that authors cite specimens using a lot of different codes, some stable, many not. Given the way taxonomists work…it might be easier (at least at the beginning) to tie together codes on the “back end” rather than have taxonomists employ standardized codes on the front end (e.g., published works).