I gather even within top pull derailleurs there are “conventional” and “top swing”….

my current frame has got a top pull front derailleur. Its cable connects to the outside of the derailleur itself, i.e. the side nearest the largest chain ring.
So is this “top swing” or “conventional”…?

also am I right in thinking I could have either a “top swing” OR a conventional with a 4-bar linkage frame, but on a single pivot frame like an orange five or a santa cruz heckler i could only have the type of front mech where it connects from the back – whatever this is called, the opposite of what i’ve currently got.

In other words if i changed frame from a 4 bar to a single pivot would i have to buy a new front mech.

Conventional = high band
Top swing = low band

It’s really about where the clamp sits in relation to the cage. A conventional mech has the clamp above the cage. I have a Turner 5spot and all the BB area is taken up with pivots and CNCd BB gubbins, so there just isn’t room for a low clamp(top swing) mech. On my old Marin FS bike, top swing is all you can fit as the high clamp would foul the swingarm. On most hardtails it makes no odds which you fit, though on some the high clamp can get in the way of bottle cage fitting. Where the cable comes from, is whether it’s top pull(a stop somewhere on the seat tube, usually) or bottom (usually through a plastic guide under the BB) pull. Most mechs allow for both cable routes these days, but some are more elegant than others.

Conventional (like on road bikes) – definitely the best option assuming that you don’t have a full susser that it won’t fit as they last much longer before going wobbly.

Top Swing – good for only one thing – full sussers where a conventional mech won’t fit.

High clamp bottom swing (conventional) front mechs tend to last a LOT longer than low clamp top swing mechs. So if you can fit a conventional one.

conventional are heavier if that’s your thing. I’ve just changed from a top swing to a conventional and after years of troublesome shifting it is finely solved. A top swing (as fitted from new) does not have enough clearance on the frame to allow proper shifting to the granny ring.