He recommended that software developers attach express patent licenses to free and open source software license schemes such as Open BSD and the GNU General Public License.
The Manhattan-based lawyer, who works for the FSF on a pro bono basis, made the recommendation during a seminar supported by Red Hat and global law firm Phillips Fox in Sydney on Wednesday.
While most concerns about using free and open source software in the post-SCO era have orbited around the notion of inadvertent patent infringement, yesterday solicitors raised concerns that open source licensors might grant rights to infringe on their proprietary patents inadvertently.
"When the GPL -- which is one of the licenses that doesn't have an express patent license -- doesn't say anything about [patent licensing] that doesn't mean that there's no right to practice the patents of the company that is licensing the software to you," said Ravicher.
The comments raised concerns that distributing code under an free and open source license may grant downstream developers rights to infringe on other software patents held by the developer unknowingly.
Ravicher conceded that there was a "grey area" around the question of what patent rights are implied in open source licenses.
However, backed by Red Hat senior vice president, Mark Webbink, he said the inclusion of express patent licenses would eliminate that possibility.
The recommendation comes amidst increasing activity among Australian legal minds, picking over the intellectual property ramifications of using open source software.
Last month, Deacons intellectual property solicitor, Nick Abrahams told ZDNet Australia that he had noted an increase in the number of Australian businesses seeking legal advice about using free and open source software.
The Phillips Fox seminar coincided with a similar event held across town at the offices of Baker & McKenzie with the support of local open source advocates Linux Australia and Open Source Industry Australia (OSIA).
As ZDNet Australia  reported yesterday, at that event Baker & McKenzie partner John MacPhail, struck fear into the hearts of developers declaring that patents were being used as "anm offensive weapon".
Ravicher argued that "patents pose less of a threat to open source software than they do to proprietary software" in the United States.
"There are no patents that choose only to be infringed by open source [software]. Any patent that imposes a threat to open source software is going to impose a threat to proprietary software," said Ravicher.