Three year catch up only once??

[smm]

The preamble to the 457 regulations states that a participant may not elect to have the special 3-year 457 catch up election apply more than once..........unless the participant is covered by the plan of another employer (etc..)...

The first paragraph of Section©(3)(i) of the regulations states that the plan ceiling can be raised for one or more of the participant's last 3 taxable years.......

It is possible that I overlooked another cite in the regulations, but assuming a participant is otherwise eligible, how many times may the limit be increased?

Thanks.

[joel]

If one has already used the DAR with one plan he/she may not use it with a subsequent employer's plan.