The index of this alert in the alert table. This table is expected to be rather dynamic, with rows added as alert conditions occur on devices, and then the rows being removed as alert conditions are cleared. The data in this table should not persist over a POR, but should be reset when the printer is reset, with appropriated items being added back in as the printer finds them. While this OID is marked as read-only, it should not be returned as table-column, which means it should be treated as not-accessible. It is marked as read-only in the MIB only because many MIB compilers will complain about this being called not-accessible since the trap can return this index.