This enum is used with the attributeusage attribute.
public enum AttributeTargets { Assembly = 0x0001; Module = 0x0002; Class = 0x0004; Struct = 0x0008; Enum = 0x0010; Constructor = 0x0020; Method = 0x0040; Property = 0x0080; Field = 0x0100; Event = 0x0200; Interface = 0x0400; Parameter = 0x0800; Delegate = 0x1000; All = Assembly | Module | Class | Struct | Enum | Constructor | Method | Property | Field | Event | Interface | Parameter | Delegate; ClassMembers = Class | Struct | Enum | Constructor | Method | Property | Field | Event | Delegate | Interface;