| Annotation | This enumerator value is reserved and should not be used. | 
| Macro | These are Microsoft intermediate language (MSIL) instructions that are used as a synonym for other MSIL instructions. For example, ldarg.0 represents the ldarg0 instruction. | 
| Nternal | Describes a reserved Microsoft intermediate language (MSIL) instruction. | 
| Objmodel | Describes a Microsoft intermediate language (MSIL) instruction that applies to objects. | 
| Prefix | Describes a prefix instruction that modifies the behavior of the following instruction. | 
| Primitive |  |