The “standard” would be considered a dialect, as well.
One of my professors particularly enjoys pointing out that there is no such thing as Standard English (a point with which I agree wholeheartedly). If you poll all English speakers, you will get a multitude of different answers to this query - for instance, Brits might say RP is standard while Americans might refer to the elusive accent usually used by news anchors.
The topic of varities of English in particular is amazingly broad because there are just so many - and they are not always mutually intelligible... for instance, Jamaican English as it is spoken among L1 speakers is barely understandable to me, a Canadian English speaker. Last year I borrowed a DVD of a movie called Dancehall Queen, entirely in Jamaican English, and had to watch with subtitles.
I also recall referring to age-lects as chronolects; that was in a French course, but I had assumed the same word would be used in English as well...
Idiolects are interesting; I have a friend who pparticularly likes to push the boundaries of English by using words of dubious validity such as "oftenly". Particularly interesting are idiolects which involve code-switching.
Julie
