Technically, because it is a private-letter ruling (No. 9110016), it sets no legal precedent for other cases.

The other is requests for private-letter rulings, questions posed by groups about whether something the group is considering, like a merger, might fall afoul of tax law.

The I.R.S. policy was detailed in a private-letter ruling issued Jan. 19 to an unnamed international law firm.

A private-letter ruling applies only to the taxpayer who requested it, but it "gives you an idea of the government's thinking," Mr. Kess said.

The I.R.S. general counsel's office recommended that the I.R.S. revoke three previous "private-letter rulings" that the agency gave to hospitals in 1984, 1988 and 1989.

In particular cases, companies frequently seek private-letter rulings, which cover specific cases, from the Internal Revenue Service.

Check the criteria, and if necessary seek a private-letter ruling from the I.R.S.

A favorable private-letter ruling issued earlier this year has further emboldened investment bankers encouraging the technique.

Far from providing these private-letter rulings, the agency placed the requests on hold, pending results of the audits.

"You might have to get a private-letter ruling from the I.R.S.," Mr. Greenstein said, "but they seem to be dealing with these kinds of requests in a practical way."