Amid tensions surrounding their lawsuit against the producers of a "Star Trek" fan film, Paramount Pictures and CBS have released details guidelines for amateur productions.

"Throughout the years, many of you have expressed your love for the franchise through creative endeavors such as fan films," the two companies said in a statement released this morning. "So today, we want to show our appreciation by bringing fan films back to their roots."

The "Guidelines for Avoiding Objections" specify 10 rules to avoid legal action from Paramount and CBS, including the fan production cannot use "Star Trek" in the title, but must include the phrase "A 'Star Trek' Fan Production" in the subtitle.

That in itself will prove a hurdle for existing fan series like "Star Trek Continues" and "Star Trek New Voyages," but the major blow comes in the run-time limitations set by the companies: A fan production must be less than 15 minutes long for a single, self-contained story, and more than two segments that don't exceed 30 minutes in total. There can be no additional seasons, episodes, sequels or remakes.

Paramount and CBS sued the producers of the crowd-funded prequel “Star Trek Axanar" in December, a move that surprised fans and professionals alike, as the rights holders had long tolerated -- and even encouraged -- fan productions. “Star Trek Beyond” director Justin Lin sided with fans in March, tweeting, “This is getting ridiculous! I support the fans. Trek belongs to all of us.”

Just last month J.J. Abrams announced at a fan event that Lin helped to convince Paramount executives to drop the lawsuit, but as of last week the litigation was inching forward.

The new guidelines also dictate that fan productions may not be remakes of "Star Trek" films or episodes, must use bootlegs or imitations of commercially available uniforms or props, and cannot use any writers or actors who have previously been employed on a "Star Trek" series or movie.