In exceptional cases, this may be 15 years or longer.

The last two exceptional cases were the most difficult to find.

That authority is only to be used in exceptional cases.

In one exceptional case, however, technology may end a debate.

So I think people shouldn't read this exceptional case as being something more than it's not.

But that was, and should remain, a very exceptional case.

However, this was an exceptional case, because such things have not happened in Russia itself for a long time.

The information should only need to be kept in a few exceptional cases.

These exceptional cases will be considered in detail later on.

But in politics there are exceptional cases and this is one of them.