SR - family designation, like KA/CA/RB/VG/VQ/etc
20 - 2.0 litres
D - DOHC (2 cams, overhead, timing chain driven, hydraulically lifted)
E - Electronic fuel injection
T- Turbo

SR20DE and SR20VE are non-turbo, they dont have the T

to spot an SR, look at the valve cover. besides the oil cap placement, check for a turbo, and most SR's will still have the coilpack cover (much like a plug wire cover on a Vtec Honda motor). SR's use no distributor, so if there is a distributor it's probably a KA (some of the earliest swaps back in the late 1990s used distributors but you wont see that anymore). if you see plug wires its likely a KA.