iPod owners have begun receiving notices in the past few days that they may be eligible for inclusion in a class-action lawsuit against Apple concerning steps the company took to steps to prevent music purchased from the RealPlayer Music Store from playing on iPods. In November suit was awarded class-action status, meaning that anyone who bought an iPod in the relevant time period is eligible for inclusion.

Since the launch of the iTunes Music Store, iPod owners have had two options for playing music on their devices: they can play music files that are in open formats like MP3, or they can play files that have been downloaded from the iTunes Store. Files downloaded from other sources that are not in a compatible DRM-free format are not playable. In 2004, RealNetworks decided that they were not content with that situation, and created Harmony, a software program that would convert the Helix DRM placed on RealPlayer downloads to the FairPlay DRM format that was in use on songs from the iTunes Music Store at the time.

This, as you might imagine, didn’t sit well with Apple, who released a software update for the iPod that blocked Harmony’s functionality. Apple’s actions, in turn, didn’t sit so well with RealPlayer users, some of whom decided to sue Apple for anti-competitive practices. The original complaint (PDF) was filed in 2010. You can see the notice that some iPod owners have been getting below:

Final NOP Email 5-3-12

So, how do you qualify as a member of the class? It’s pretty simple, actually: all you have to do is have purchased an iPod (almost any iPod) between September 12, 2006 and March 31, 2009. If you want to be included in the class, you don’t have to do anything – just allow things to proceed. In doing so, of course, you forfeit your right to sue on your own. If for some reason you were thinking of suing Apple over this yourself, or you don’t want to be included for any other reason, you need to send an exclusion request by the end of July. Instructions for doing so are in the document above, and on a special lawsuit set up for the case: ipodlawsuit.com.

Of course, even if you do elect to remain part of the class, there’s no guarantee that you’ll actually get anything. The case is still working its way through the court system, and no determinations have been made. In other words, the court could easily decide that Apple did nothing wrong, and that the members of the class aren’t entitled to anything.

Did you buy an iPod between Septemer 2006 and March 2009? Were you inconvenienced by Apple’s blocking of RealPlayer songs? Should Apple have to pay iPod users for its actions? Let us know what you think in the comments.