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.