The PENDINGTYPE enumeration constants indicate the level of nesting in the IMessageFilter::MessagePending method.
typedef enum tagPENDINGTYPE
{
PENDINGTYPE_TOPLEVEL = 1,
PENDINGTYPE_NESTED = 2
} PENDINGTYPE;
Windows NT: Use version 3.1 and later.
Windows: Use Windows 95 and later.
Windows CE: Unsupported.
Header: Declared in objidl.h.
IMessageFilter::MessagePending