Does anyone have a definition that may have appeared in a document or article or otherwise in some written format or provided by their examiners as to what "best practices" is, that is, have any of you ever seen "best practices" defined in a regulation or otherwise, especially in the context of all the monitoring, etc. now required and expected in our AML programs? We see this term all the time now but it is so vague, best practices for us may not be the same as for you.

"Best Practices" is one of those "I'll know it when I see it" things. What are the things you see other banks doing that make you say "I wish we could do that." Or, the things that make you say "Sure, they can do that. It would never work here."

Well, since most of the BSA/AML procedures that you establish are risk-based, 'best practices' would be whatever is considered the wisest choice/practice for a bank of your size based on your customer portfolio.
If everyone in your region and of your size is establishing
a certain level of monitoring and procedures, then that level would be considered the best practices.