Historical 
RFC 1156 - Management Information Base Network Management of TCP/IP based internets 
RFC 1161 - SNMP over OSI 

Informational 
RFC 1215 - A Convention for Defining Traps for use with the SNMP 
RFC 1270 - SNMP Communication Services 
RFC 1303 - A Convention for Describing SNMP-based Agents 
RFC 1470 - A Network Management Tool Catalog 

Standard and Draft 
RFC 1089 - SNMP over Ethernet 
RFC 1140 - IAB Official Protocol Standards 
RFC 1155 - Structure and Identification of Management Information for TCP/IP based internets. 
RFC 1157 - A Simple Network Management Protocol 
RFC 1158 - Management Information Base Network Management of TCP/IP based internets: MIB-II 
RFC 1187 - Bulk Table Retrieval with the SNMP 
RFC 1212 - Concise MIB Definitions 
RFC 1213 - Management Information Base for Network Management of TCP/IP-based internets: MIB-II 
RFC 1224 - Techniques for Managing Asynchronously-Generated Alerts 
RFC 1418 - SNMP over OSI 
RFC 1419 - SNMP over AppleTalk 
RFC 1420 - SNMP over IPX