Has anyone ever heard of this?

On the one hand, it sounds like it could be a disabled life mortality table.

On the other, it sounds like it could be a recovery from disability table.

The Society of Actuaries has published some tables on disability continuance and disability mortality.

I encourage you to explore the ACORD project and the XTBML tables at the soa.org web site.

If you are taking over a plan that used this table, you should make the request of the former actuary
for a copy of the table used, or at least the source of the table. Perhaps you would be better served
if the client makes the request.

There is a Rose Bowl joke here somewhere, but I just can't point my finger on it.