TO-220 Packages and their various flavors

Does anyone have a good resource for TO-220 package definitions, specifically with respect to the various flavors denoted by AB, F etc.

The reason I ask it that, from my perusal of various datasheets, it seems that the tab for a plain old TO-220 is electrically isolated from the package leads themselves, while for the TO-220AB, the tab can be part of the electrical package (for example it could be a replicate drain on a MOSFET).

I am trying to figure out if I can "bolt" a number of TO-220s (each a different component in a circuit) to a common heatsink without having to get the "special" hardware (insulators etc).

Thanks in advance

Most likely the tab on a TO-220 is ‘hot’ electrically. You need to check the data sheet for each transistor you use. There is an insulated TO-220. see JPG