Smileys and toggles are used to indicate that something we have written is a joke or is not serious. (A toggle is a switch that goes on-off-on-off-on-off.)
Smiley marks are named after the most famous mark of them all. Try looking at it sideways:
:)
There are many other smileys, however, and not all of them indicate a smile. For example:
;) = wink :( = frown
Some smileys are not really symbols, but words or abbreviations of words:
<grin> <G> = Grin <LOL> = Laughing Out Loud <sigh>
Smileys usually come at the end of a phrase or sentence, but if we want to show that a longer passage is a joke, or is intended to be ironical, we use toggles like these:
<irony mode on> <irony mode off>
The 'on' toggle comes at the beginning of the passage, and the 'off' toggle comes at the end.