[tubignaaso]

Also work in the FX space and could never find a good FIX specification resource. Always had to rely on whatever the broker shared with us, but it always felt incomplete. This is a super useful resource. Thanks for sharing!

[Copenjin]

Do you really need anything more than the dictionary? https://www.onixs.biz/fix-dictionary.html

Implementations varies, no one forces the third party to use message types 100% as intended.