About 10% of the business method patents issued in 2006 were appealed.

All software patents are "method" patents.

"It's a method patent, a new way of doing business," Mr. Amos said.

These are all primarily method patents and medical method patents are generally not enforceable, except through contracts.

In Quanta, the Supreme Court applied the same test to determine whether exhaustion is triggered by the licensing of method patents.

Thus, under the Univis test, the Intel products sufficiently embodied the method patents, making the exhaustion doctrine applicable.

"We are particularly happy with the idea that we got a method patent instead of just a device patent," Mr. McClelland said.

Additionally, the Federal Circuit held that the exhaustion doctrine did not apply, in any event, to method patents.

Several years later, Daugman received a method patent for the algorithm and a crudely constructed prototype proved the concept.

In 1979, Matthews also filed a method patent for voicemail, which was granted on 1 February 1983.