The System.Security.Permissions.PermissionSetAttribute properties PermissionSetAttribute.Name, PermissionSetAttribute.File, and PermissionSetAttribute.XML are mutually exclusive, meaning that a permission set can have as its source only one of the following: a named permission set, a file containing an XML representation of a permission set, or a string containing an XML representation of a permission set.

The scope of the declaration that is allowed depends on the System.Security.Permissions.SecurityAction that is used. A System.Security.Permissions.SecurityAction performed on a System.Security.PermissionSet is the equivalent of performing that action on each of the permissions within the set.

The security information declared by a security attribute is stored in the metadata of the attribute target and is accessed by the system at run time. Security attributes are used only for declarative security. For imperative security, use the corresponding permission class.