The combination of two SM letters is commonly used worldwide for indicating a registered trademark. The abbreviation comes from the expression "service mark" which literally means a brand name or logo that identifies the provider of a service. In other countries there are other trademark symbols used in this context: [U:2122] or [U:00AE].

In addition, the Service Trademark Unicode symbol comes in handy as a slang abbreviation for "so much". You can use it when chatting or texting. For example, [b]I love you[/b] [U:2120].