Thanks Dream Land! Much appreciated. However, I'm still just an F/O, that too with just 600hrs TT.
To PJ2: Awesome advice... only thing is, you've got it HORRIBLY WRONG and BRILLIANTLY CORRECT, all at the same time! :-D i.e. all that you're describing is probably Boeing. I used to be a type-rated engineer on both Airbus and Boeing, so I remember those colors and indications from the 777. On the Scarebus, you said.....
1. On the FMC PROG > Descent Page, Line 2 right-side there is the VNAV PATH digital indication of deviation above/below path;
*** Actually, its called V/DEV (vertical deviation), not VNAV PATH.
2. On the ND, there is the green Energy Symbol (an arc);
*** Only in HDG mode, not in NAV mode.
3. On the PFD, to the left of the Vertical Speed display there is the magenta Vertical Dev symbol, which provides a +/- 500' window of deviation from the theoretical descent path.
*** er.. no! The "yo-yo" (official Airbus terminology) is on the Altimeter scale on the right side. The digital readout in the center of the Altimeter scale has 500' above it to the top of the scale, and 500' below it. So, you have a +/-500' deviation indication. On some airplanes, it will be a magenta hollow circle, and on others (newer FMS's) it's a solid green circle.
4. On the ND track display - the white (in non-Managed Mode) or magenta (Managed Mode descent) top-of-descent arrow & level-off arrow on the ND.
*** No such colors on the Airbus. You have Magenta if there are constraints built into the FMS, like on a SID or STAR, otherwise its Blue or White. For details refer to FCOM DSC-31-45 P 11/54.
PJ2, I'm not trying to be anal, or critical of your advice. Everything that you've described is correct, and brilliant. It's just for Boeings. WST seems new to the whole thing, and he may end up more confused than ever looking for stuff in the books or on the airplane that just isn't there.
Fly safe!