Apr 8, 2011 08:51 GMT  ·  By

Apple’s lawsuit against several companies selling unauthorized accessories for iPods, iPhones, and iPads can continue, a federal judge has ruled.

Accessory makers looking to make a buck in the iDevice business must agree to Apple’s specific licensing and certification program called MFi, in order to have clearance for legally selling their goods.

“Participate in the MFi licensing program to develop electronic accessories that connect to iPod, iPhone, and iPad,” Apple says on its Developer web site.

“Licensed developers gain access to technical documentation, hardware components, technical support and certification logos,” the note reads.

Enlisting in the program is not mandatory for all accessory makers, but only for those who use Apple hardware, such as the 30-pin connector for iOS devices.

Via Arstechnica now comes a reminder that last year, Apple sued a total of seven companies that sold such accessories without proper authorization from Apple.

"These products are frequently advertised and sold in a manner that falsely and unfairly implies affiliation with Apple and infringes Apple’s valuable intellectual property," Apple’s complaint, filed in July, said.

"Many are of inferior quality and reliability, raising significant concerns over compatibility with, and damage to, Apple’s products."

According to the aforementioned technology site, two of the companies cited in the suit ended up settling.

In the meanwhile, a third one was dropped from the case when it failed to respond to the lawsuit.

Four companies selling unauthorized accessories for iDevices remain targeted by the original suit.

Defended by eForCity, they argue that Apple failed to identify the specific patent claims that their products infringed upon.

However, US District Judge Jeremy Fogel has ordered the lawsuit to proceed, after noting in his order denying the motion that such specific claims are not required.

In fact, these aren't due until after case management has been determined, he reportedly pointed out to eForCity.