I found the post I was remembering it was from the facebook group on August 23. Hopefullly this link will work.
Renee responded to a reported problem when using emojis in the suffix field as follows:
“Using emojis can cause several issues in databases. This would be a good example of how they are not supported. I wouldn’t recommend using them as a search filter.”
[edit] I noticed that the help doc for these fields says “Enter any text …”. I am not aware of any official statement of the specific character set types that are supported in these fields. It would be great if all unicode characters were supported to enable things like you are suggesting.