Complete Protocol dictionary, glossary and reference
SNMP SMI: SNMP Structure of Management Information
SNMP Structure of Management Information (SNMP-SMI) is a collection of managed objects, residing in a virtual information store. The SMI is divided into three parts: module definitions, object definitions, and, notification definitions. There are two types of SMI: SMIv1 and SMIv2.
RFC 1155 v1 and RFC 2578 v2