OK, here's another approach to ponder.

If folks can't distinguish between acronyms, abbreviations, and that which we are defining as SMS, then you probably should go to the other extreme and let it all come flowing in. Then simply state in the Forum rules and etiquette that SMS is frowned upon and that its use may cause others to ignore posts that use it and thus not reply. The rule for post deletion regarding SMS would be that any post complaining about SMS gets deleted. This way, those who want to use SMS amongst the SMS-tolerant, can do so. Those who will not tolerate it will ignore those posts without complaint or reply (I stopped whining and started ignoring posts quite some time ago).

So it all ends up being sort of self-moderating -- if it's important for one to hopefully solicit a reply from those on record as SMS-intolerant, then don't use SMS. If one doesn't care about that, or just wants to lazily "chat" with their buddies can do so.