C

cacheFile
cacheFileCombine
cacheFileMerge
cacheFileTrack
camera
cameraView
canCreateManip
canvas
capitalizeString 
catch
catchQuiet
CBG 
ceil
changeSubdivComponentDisplayLevel
changeSubdivRegion
channelBox
character
characterize
characterMap
characterOutlineEditor
chdir
checkBox
checkBoxGrp
checkDefaultRenderGlobals
choice
circle
circularFillet
clamp
clear
clearCache
clearParticleStartState 
clip
clipEditor
clipEditorCurrentTimeCtx
clipSchedule
clipSchedulerOutliner
clipTrimBefore 
closeCurve
closeSurface
cluster
cmdFileOutput
cmdScrollFieldExecuter
cmdScrollFieldReporter
cmdShell
coarsenSubdivSelectionList
collision
color
colorAtPoint
colorEditor
colorIndex
colorIndexSliderGrp
colorSliderButtonGrp
colorSliderGrp
columnLayout
commandEcho
commandLine
commandPort
compactHairSystem 
componentEditor
compositingInterop
computePolysetVolume 
condition
cone
confirmDialog
connectAttr
connectControl
connectDynamic
connectionInfo
connectJoint
constrain
constrainValue
constructionHistory
container
containerAutopublishRoot 
containerProxy
containerRmbMenu 
containerTemplate
containerView
containsMultibyte 
contextInfo
control
convertFromOldLayers 
convertIffToPsd
convertLightmap
convertSolidTx
convertTessellation
convertUnit
copyArray 
copyAttr
copyFlexor
copyKey
copySkinWeights
cos
createCurveField 
createDisplayLayer
createDrawCtx
createEditor
createHairCurveNode 
createLayeredPsdFile
createMotionField 
createNConstraint 
createNewShelf 
createNode
createRenderLayer
createSubdivRegion
cross
crossProduct 
ctxAbort
ctxCompletion
ctxEditMode
ctxTraverse
currentCtx
currentTime
currentTimeCtx
currentUnit
curve
curveAddPtCtx
curveCVCtx
curveEditorCtx
curveEPCtx
curveIntersect
curveMoveEPCtx
curveOnSurface
curveSketchCtx
cutKey
cycleCheck
cylinder

indicates a MEL script