Functions with hidden parameters

To define functions that require arguments for hidden parameters, the name is prefixed with the function type. For example, if you look at the IDL definition for the DefinedCategories function shown above, you can see that it has an MR_LCIDMDMID_ prefix. This prefix is made up of a number of subprefixes.

Function type	Subprefix	Description
Standard	None	All functions that do not contain hidden parameters.
Generic	MR_	Generic prefix that must always precede any of the other prefixes.
Runtime	RT	Functions that require the scripting runtime. This can be either the script engine (IScriptEngine) and a script program (IScriptProgram) or the evaluate engine (IEvaluate) and an expression program (IExpressionProgram). The first hidden argument is the scripting engine and the second is the script program.
Value Interface	IVAL	Functions that require direct access to the IValue interface associated with a value. The first hidden argument for this prefix is the value interface and the second is the identifier name.
Locale	LCID	Functions that require the input and output locale IDs to be passed as hidden arguments. The first hidden argument for this prefix is the input locale ID and the second is the output locale ID.
MDM	MDM	Functions that require an instantiated level object pointer of type IUnknown as a hidden argument, so that the IArray interface can be used to access the level object's Fields or Types collections. The level object can be a MDM Document, an Array or a Grid.
Identifier	ID	Functions that require the identifier name as a hidden argument. The value passed is the RelativeName of the object containing elements, in the level object's Fields or Types collections.