*Warning* ET cfg questions

What do these commands do :

seta com_soundmegs
seta com_zoneMegs
seta cg_coronafardist
seta cg_fastSolids
seta cg_vertexlight
seta cg_announcer
seta cg_predictItems
seta cg_muzzleFlash
seta r_cache
seta r_textureMode
seta r_intensity
seta r_picmip2


Update

seta r_lodcurveerror "250"
seta r_ignoreFastPath "0"
seta r_ignoreGLErrors "1"
seta r_roundImagesDown "1"
seta r_vertexLight "1"


Going throw my cfg and trying to see how can i make ET more smoother for me but i am not that good with cfg's. Thx for help & whine.