A lot of these are new, and not much known about them yet.
vsync=0 - Can force a sync rate of your monitor, if you are getting tearing.
superflatterrain=0 - Sets the terrain to a flat non editable plane, with very little polys I it.
riftmode=0 - For using occulus rift viewer
smoothcamerakeys=0
memorydetector=0
occlusionmode=1
occlusionsize=0
hidememorygauge=0 - setting this to 1 will hide the memory gauge in the upper left corner
hidelowfpswarning=0 - Setting this to 1 will hide the low FPS warning dialog.
hardwareinfomode=1 - Turns off F11 mode
reflectionrendersize=512 - Sets the size of the reflection map. the larger the better, but at a performance cost.
fullscreen=0
width=-1
height=-1
depth=32
aspectratio=1 - forces aspect of your minitor
producelogfiles=1 - setting this to 0 does not write the log file upon loading FPM files.
producetruevidmemreading=0 - Something to do with reading graphics memory I think.
charactercapsulescale=100 - Changes the percentage of the size of the collision capsule of characters.
ignoretitlepage=1 - Setting this to 0 ignores title pages and wont display.
invmouse=0 - setting this to 1 inverts the mouse movement.
disablerightmousehold=0 - setting this to 1 disables right mouse button click
profileinstandalone=1
deactivateconkit=1
adapterordinal=0 - Force the use of a second graphics card over the first. set this to 1
hideallhuds=0
Some of these are self explanatory. The rest deal with remapping keys.
Hope that helps.
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4 Logical Processor(s), 8gb RAM, Nvidia gtx660, Windows 7 Pro 64bit