The Cupertino, Calif.-based company has sent cease-and-desist letters to at least two companies that include the word "pod" in their product titles, in connection with its iPod digital-music players.
Apple asked both companies to rename their products, arguing that they infringe on its iPod trademark.
Sarah Wright, intellectual-property solicitor at law firm Olswang, said Apple's letters are not unusual. The Mac maker may not expect or intend to take the matter all the way to court, she said.
"It's common practice for big-brand owners to send letters like this...If they don't police their brand properly and ensure that trademarks that are too similar to their brands don't get on the register, it makes it more difficult to enforce their rights against third parties," she said.
A blog on sister site ZDNet News posted what purports to be a letter from Apple's lawyers to Carolee and Dave Ellison, who run Mach5products. The letter reads: "We believe there is confusing similarity between Apple's iPod mark and the Profit Pod mark. Both devices receive and transmit data, and are used with computers, both are used in connection with video games, and both have other similar components. Moreover, it has not gone unnoticed that, like Apple's iPod device, the Profit Pod product is a small, flat, round-cornered rectangular device with a display screen."
Mach5products also applied for a patent on the name of its product in 2004, an action Apple requested the company rescind in its letter.
Wright said the trademark filing may have been the catalyst for Apple's move. "Often, people think they must get a trademark," she said. "Sometimes they're better off not getting one and acquiring rights through trading...and avoid getting into these kind of scrapes."
TightPod has also been instructed to abandon a trademark application it had filed to cover the TightPod in relation to MP3 players, with Apple once again citing possible confusion with its iPod.
Terry Wilson, who makes and sells TightPods, has responded by offering to remove the reference to MP3 players or for Apple to pay half the cost of rebranding efforts. Wilson is also considering going to court over the matter.
Apple did not respond to requests for comment.
This is not the first time the company has used legal means to protect its iPod trademark. Apple sued a German company over its Spodradio product earlier this year.
Jo Best of Silicon.com reported from London.