What? No B shares?
This is what happens when you have fund families that try to sell funds through all channels - traditional (load-based) advisors, wrap accounts, direct retail, supermarket, retirement plan, and institutional. Three families come to mind - Janus, PIMCO, and American Century. I'm sure there are others.
Anyway, though Janus uses a couple of unconventional letters for some of their share classes, the classes you listed follow these basic channels:
traditional load - A, C (front load, level load)
D - direct retail sale (no 12b-1 fee, but 0.12% admin fee, for bookkeeping)
I - institutional (no admin/12b-1 fees)
N - retirement (no admin/12b-1 fees)
T - supermarket (0.2
5% admin fee)
S - wrap accounts (0.2
5% admin fee, plus 0.2
5% 12b-1 fee)
Some more common designations are Inv(estor) for directly sold noload shares, Adv(isor) for wrap or supermarket shares.
Many families use R to denote retirement class shares (or just use I shares w/o creating a different share class).
Usually, fund families use the same share class for more than one channel, which is why you don't often see as many as seven (or eight, with B shares) different classes.
(I'm not going into families that charge different fees depending on how big the account is - notably American Funds; but also
Vanguard with Investor/Admiral, Institutional/Institutional Plus, Signal, ETF. These are just a couple of the more obvious families.)
For all this confusion, one nice thing about Janus is that if you're buying on your own, you only have to worry about T class (unless you're one of the grandfathered investors buying directly from Janus, in which case you just look at D shares). You don't have to think about multiple share classes.
