Threshold records are deprecated.
An account can stipulate thresholds for sending and receiving hbars. If an amount of hbars greater than a threshold moves in or out of the account, a record for that transaction will be persisted for 24 hours rather than the default 3 minutes. The account that stipulated the thresholds will pay for that record. Any clients that subsequently query for that record (within the 24 hours before it is deleted) will pay for that query.