Is the next indexing parameter that allows multiple, like restrictions. It is has a default value of 1 and is incremented each time its index value is used. This is an independent value and must be specified as the next added index (regardless of the restriction type). In the event there is a collision due to a race with reading the current value, the 'losing' restriction is denied and the value should be re-read for a next attempt. The value is always 1 whenever a new Entity record is created.