A question about the DEP/ARR page of the 747 FMC

[Guest visualchaosfx]

Its been a while since I been on here. I've been doing other things and stuff and now I'm trying to get back into the whole flight simming experience again. Anyways I was wondering what exactly do I put into this line here and what does it do:I did look in the owners manual but I didn't find anything related to what I circled on the image.

[cowpatz]

Selecting VFR approach will insert a discontinuity (on the legs page)and then enters a straight-in VFR approach.VFR approach begins with a VFR final approach fix (FAXXX) which is 8 miles from the runway threshold with and airspeed/altitude constraint of 170/2000 feet above the runway elevation. The 8 nm distance cannot be changed.The VFR approach ends with a runway altitude constraint of 50 ft. It will also display RWY EXT 8.0 NM.Displays FPA (flight path angle) 3.0 degrees (symbol not word). This can be changed (2.4 to 3.7 is valid).The VFR approach is a level path until the VNAV descent path is intercepted.The RWY EXT allows entry of end of descent for VNAV guidance. It creates a runway extension fix along the runway centreline for LNAV guidance. A valid entry would be from 1.0 nm to 25.0 nm.An entry here will delete the VFR APPR prompt.In essence it is a quick way of setting up a waypoint with a speed and altitude already assigned that is reasonable for a Visual approach, Selecting either of these will also dial up the ILS frequency if there is one available for that runway selection.Hope this helps.