# How do I get a list of allowed values for an option?

When using Mathematica how can I get a list of the allowed values of an option? As an example I can use the Options command as follows -

Options[Manipulate]


which gives me a list of available options

(* {Alignment->Automatic,AppearanceElements->Automatic,AutoAction->\
False,AutorunSequencing->Automatic,BaselinePosition->Automatic,\
BaseStyle->{},Bookmarks->{},ContentSize->Automatic,ContinuousAction->\
ControllerMethod->Automatic,ControllerPath->Automatic,\
ControlPlacement->Automatic,ControlType->Automatic,DefaultBaseStyle->\
"Manipulate",DefaultLabelStyle->"ManipulateLabel",Deinitialization:>\
None,Deployed->False,Evaluator->Automatic,Frame->False,FrameLabel->\
None,FrameMargins->Automatic,ImageMargins->0,Initialization:>None,\
InterpolationOrder->Automatic,LabelStyle->{},LocalizeVariables->True,\
Method->{},Paneled->True,PreserveImageOptions->True,RotateLabel->\
False,SaveDefinitions->False,ShrinkingDelay->0,\
SynchronousInitialization->True,SynchronousUpdating->Automatic,\
TouchscreenAutoZoom->False,TouchscreenControlPlacement->Automatic,\
TrackedSymbols->Full,UnsavedVariables:>None,UntrackedVariables:>None} \
*)


I can use Options for a specific parameter, i.e.,

Options[Manipulate,ControlType]
(* {ControlType->Automatic} *)


But this doesn't tell me what the possible allowed values are for this option. Checkbox, Setter etc. Is there a command I can use to find the allowed values of an option?

-
I think this was already asked here stackoverflow.com/questions/8718912/… –  belisarius Feb 13 '13 at 12:33

Unfortunately, there is no command which tells you that. There are several reasons for that. First, the possible option values are context dependent. This means, e.g. the option Method can be set to different values depending on whether you use it in NDSolve, FindRoot, etc..
Second, as you see with "Elements" or "ImageList" options of Export, options are not always symbols, but usage messages cannot be applied to strings and documentation to string options rarely exists as separate page.
1. You want to know what the special option ControlType of Manipulate does, then you first check out the help page of Manipulate