The com.ms.security.permissions package has the following hierarchy:
Object | +--ClientStoragePermission (IPermission, IEncodablePermission, Cloneable) | +--ExecutionPermission (IPermission, IEncodablePermission) | +--ExecutionRequest (ISecurityRequest) | +--FileIOPermission (IPermission, IEncodablePermission, IAdjustablePermission) | +--FileIORequest (ISecurityRequest) | +--MultimediaPermission (IPermission, IEncodablePermission) | +--NetIOPermission (IPermission, IEncodablePermission, IAdjustablePermission) | +--NetIORequest (ISecurityRequest) | +--PrintingPermission (IPermission, IEncodablePermission) | +--PropertyAccessRequest (ISecurityRequest) | +--PropertyPermission (IPermission, IEncodablePermission) | +--ReflectionPermission (IPermission, IEncodablePermission, IAdjustablePermission) | +--ReflectionRequest (ISecurityRequest) | +--RegistryPermission (IPermission, IEncodablePermission) | +--RegistryRequest (ISecurityRequest) | +--SecurityPermission (IPermission, IEncodablePermission) | +--SystemStreamsPermission (IPermission, IEncodablePermission) | +--ThreadPermission (IPermission, IEncodablePermission, IAdjustablePermission) | +--UIAccessRequest (ISecurityRequest) | +--UIPermission (IPermission, IEncodablePermission) | +--UserFileIOAccess (ISecurityRequest) | +--UserFileIOPermission (IPermission, IEncodablePermission)