The points are periodically renewed through some means; usually by the passage of time.
Government employees who hold security clearances must have them renewed periodically.
But the signals fade with distance and have to be renewed periodically.
The works were leased out in 1746, and the lease was renewed periodically until 1818.
"After a while, people grow apart if they don't periodically renew their intimacy."
In 1969 they began moving to Israel, entering the country on temporary visas that were periodically renewed.
The protocol must be renewed periodically, and has lapsed at least twice since it was signed.
Even then, this coating will wear off in time and will have to be renewed periodically.
In Muscat it was based on formal agreements that were renewed periodically.
The degradation in the long term can not be stopped completely, unless the rustproofing is periodically renewed.