There are several "special" characters commonly used when dealing with Mac systems. The most obvious is the "cloverleaf" character, "⌘", which is used for keyboard shortcuts (such as "⌘Q" to quit an application.
This is a list of them, along with the codes needed to use them in web pages (like I did above.)
|⌘||⌘||⌘||Command (aka "Cloverleaf", or "Open Apple")|
|⌦||⌦||⌦||Delete (delete to the right)|
|⌫||⌫||⌫||Backspace (delete to the left)|
|▶||▶||▶||Disclosure triangle, closed, large|
|▸||▸||▸||Disclosure triangle, closed, small|
|▼||▼||▼||Disclosure triangle, open, large|
|▾||▾||▾||Disclosure triangle, open, small|
|||||||Apple (closed apple)|
If you know of any which I've missed, which logically belong here, please let me know and I'll add them.