Twitter officially patented its “pull-to-refresh” technology for streaming on its mobile app today, The Verge reports. But Twitter also has an original, internal approach to patent applications.

All Twitter’s patents include a contract in which the company agrees to engage in patent litigation only if they are sued first. The contract is meant to deal with the concerns of the engineers whose work is being patented, and who feel the definition of defensive litigation can be fuzzy.

“[Engineers] were going around saying we’re worried about what patents mean,” said Twitter IP attorney Ben Lee, who drafted the IPA and guided it through the revision process. “The IPA is an expression of the values of the company.”

Lee’s work on the IPA began during his initial job interview with Twitter general counsel Alex Macgillivray in November of 2010. “The notion of trying to come up with new ways of handling patents was a major reason for me coming to Twitter in the first place,” he said. “I don’t think it was that long after that we were already having significant conversations with the engineers and senior management about some things we could do.”

Unfortunately, work on the IPA was put on hold not long after Lee joined Twitter — a patent troll had sued the company over a junk patent on “virtual communities,” and Lee spent serious time living in a Virginia hotel room as the case went to trial. “We’ve seen the negative impact” of patent abuse, he says. “And we’re a young company.”