[other-attributes, hidden] statement-or-function-type statement-or-function-name
[hidden, vararg]
SAFEARRAY (int) SecretFunc ([in, out] SAFEARRAY (variant) *varP) ;
[uuid(. . .), hidden, version (3.0)] library HiddenLib {. . .};
The hidden attribute indicates that the item exists but should not be displayed in a user-oriented browser. This attribute allows you to remove members from your interface (by shielding them from further use) while maintaining compatibility with existing code. You can use the hidden attribute on properties, methods, and the coclass, dispinterface, interface, and library statements.
When specified for a library, the hidden attribute prevents the entire library from being displayed. This usage is intended for use with controls. Hosts need to create a new type library that wraps the control with extended properties.
VARFLAG_FHIDDEN, FUNCFLAG_FHIDDEN, TYPEFLAG_FHIDDEN
TYPEFLAGS, dispinterface, coclass, ODL File Syntax, ODL File Example, Generating a Type Library With MIDL