Emoji Encoding

[therother]

I'm afraid the more exotic characters have always been a black box for me as well.

As to why some won't work on the Org, I suspect this is due to the database using the (then) default MySQL database collation latin1, which is a single byte character set. latin1 doesn't support as wide an array of characters that a multibyte character set such as utf8, which is I believe the current default. We moved to vBulletin 15 years ago, which was when the decision was made. IIRC, converting the database to utf8 isn't straightforward, particularly such a large and old database as the Org's.