From http://net-snmp.sourceforge.net/docs/mibs/NET-SNMP-VACM-MIB.txt

NET-SNMP-VACM-MIB DEFINITIONS ::= BEGIN

--
-- Defines Net-SNMP extensions to the standard VACM view table.
--

IMPORTS
    SnmpAdminString
    	FROM SNMP-FRAMEWORK-MIB

    netSnmpObjects, netSnmpGroups
	FROM NET-SNMP-MIB

    vacmGroupName, vacmAccessContextPrefix, vacmAccessSecurityModel,
    vacmAccessSecurityLevel
        FROM SNMP-VIEW-BASED-ACM-MIB

    OBJECT-TYPE, MODULE-IDENTITY
        FROM SNMPv2-SMI

    OBJECT-GROUP, NOTIFICATION-GROUP
	FROM SNMPv2-CONF

    TEXTUAL-CONVENTION, DisplayString, RowStatus, StorageType
	FROM SNMPv2-TC;


netSnmpVacmMIB MODULE-IDENTITY
    LAST-UPDATED "200608270000Z"
    ORGANIZATION "www.net-snmp.org"
    CONTACT-INFO    
	 "postal:   Wes Hardaker
                    P.O. Box 382
                    Davis CA  95617

          email:    net-snmp-coders@lists.sourceforge.net"
    DESCRIPTION
         "Defines Net-SNMP extensions to the standard VACM view table."
    REVISION     "200608270000Z"
    DESCRIPTION
        "First draft"
    ::= { netSnmpObjects 9 }


nsVacmAccessTable  OBJECT-TYPE
    SYNTAX       SEQUENCE OF NsVacmAccessEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION "Net-SNMP extensions to vacmAccessTable."
    ::= { netSnmpVacmMIB 1 }

nsVacmAccessEntry  OBJECT-TYPE
    SYNTAX       NsVacmAccessEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION "Net-SNMP extensions to vacmAccessTable."
    INDEX       { vacmGroupName,
                  vacmAccessContextPrefix,
                  vacmAccessSecurityModel,
                  vacmAccessSecurityLevel,
                  nsVacmAuthType
                }
    ::= { nsVacmAccessTable 1 }

NsVacmAccessEntry ::= SEQUENCE
    {
        nsVacmAuthType         SnmpAdminString,
        nsVacmContextMatch     INTEGER,
        nsVacmViewName         SnmpAdminString,
        nsVacmStorageType      StorageType,
        nsVacmStatus           RowStatus
    }

nsVacmAuthType OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE(0..32))
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION "The type of processing that the specified view
                 should be applied to.   See 'snmpd.conf(5)' and
                 'snmptrapd.conf(5)' for details."
    ::= { nsVacmAccessEntry 1 }

nsVacmContextMatch OBJECT-TYPE
    SYNTAX       INTEGER
                { exact (1), -- exact match of prefix and contextName
                  prefix (2) -- Only match to the prefix
                }
    MAX-ACCESS   read-create
    STATUS       current
    DESCRIPTION "If the value of this object is exact(1), then all
                 rows where the contextName exactly matches
                 vacmAccessContextPrefix are selected.

                 If the value of this object is prefix(2), then all
                 rows where the contextName whose starting octets
                 exactly match vacmAccessContextPrefix are selected.
                 This allows for a simple form of wildcarding.

                 The value of this object should be consistent across
                 all nsVacmAccessEntries corresponding to a single
                 row of the vacmAccessTable.
                "
    DEFVAL      { exact }
    ::= { nsVacmAccessEntry 2 }

nsVacmViewName OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE(0..32))
    MAX-ACCESS   read-create
    STATUS       current
    DESCRIPTION "The MIB view authorised for the appropriate style
                 of processing (as indicated by nsVacmToken).

                 The interpretation of this value is the same as for
                 the standard VACM ViewName objects."
    DEFVAL      { ''H }   -- the empty string
    ::= { nsVacmAccessEntry 3 }


nsVacmStorageType OBJECT-TYPE
    SYNTAX       StorageType
    MAX-ACCESS   read-create
    STATUS       current
    DESCRIPTION "The storage type for this (group of) conceptual rows.

                 Conceptual rows having the value 'permanent' need not
                 allow write-access to any columnar objects in the row.

                 The value of this object should be consistent across
                 all nsVacmAccessEntries corresponding to a single
                 row of the vacmAccessTable.
                "
    DEFVAL      { nonVolatile }
    ::= { nsVacmAccessEntry 4 }

nsVacmStatus OBJECT-TYPE
    SYNTAX       RowStatus
    MAX-ACCESS   read-create
    STATUS       current
    DESCRIPTION "The status of this (group of) conceptual rows.

                 The  RowStatus TC [RFC2579] requires that this
                 DESCRIPTION clause states under which circumstances
                 other objects in this row can be modified:

                 The value of this object has no effect on whether
                 other objects in this conceptual row can be modified.

                 The value of this object should be consistent across
                 all nsVacmAccessEntries corresponding to a single
                 row of the vacmAccessTable.
                "
    ::= { nsVacmAccessEntry 5 }

END