Here’s how you know how enamored Dell is with the Netbook concept: it’s volunteered to fight over the trademark on behalf of all other Netbook makers.

On Wednesday the PC maker filed a petition with the U.S. Patent and Trademark Office to cancel a registered trademark for the term «Netbook» by a company called Psion.

Psion is a Canadian mobile computer maker that owns the trademark and indeed has sold a product called Netbook in the past. Psion began sending some tech bloggers and Netbook makers cease-and-desist notices late last year asking them to stop using the term «Netbook.» It’s what you’re supposed to do when you own a trademark: defend it.

But Dell is taking the legal step of accusing the company of failing to defend it properly, not actually using the term for any current products--or for the last six years--and for lying about it. (See Dell’s petition to the USPTO here.)

Dell’s point in the filing that the term is generic seems valid. Not only Dell, but Asus, Hewlett-Packard, Acer, Lenovo, LG Electronics, Samsung, MSI, and many others have been using Netbook as a blanket term to describe small form-factor laptops with low-power processors, usually Intel’s Atom chip, for over a year.

Dell has three products that fall under the Netbook category, the Inspiron Mini 9, Mini 10, and Mini 12, but it’s not entirely clear why the company has volunteered for this fight. Is it feeling charitable? Or suddenly passionate about patent and trademark reform? Note that this is the same company that tried to trademark «cloud computing.»