If you do not use the default internal CLR reflection technique for a XamlType, calls to this property can invoke LookupIsPublic overrides on XamlType derived classes.
LookupIsPublic is virtual, and therefore, can be overridden. The override has the potential (whether for malicious purposes or otherwise) to change the reported access information about a XAML type so that it no longer aligns in an expected way with the type system and access information of its underlying CLR type. For any security-critical checks of assignment operations and access, use the underlying CLR type instead.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)