While the Federal Communications Commission passed its net neutrality rules on February 26, they weren't published in the Federal Register until today.

The publication means a couple of things: the rules go into effect 60 days from today, and parties that oppose the rules have 10 days to file lawsuits against the FCC. (Technically, they have 60 days, but there are advantages to filing within the first 10.) Almost immediately after publication, a trade group representing ISPs called USTelecom filed suit in the US Court of Appeals for the District of Columbia Circuit.

USTelecom's petition said the FCC's ruling is "arbitrary, capricious, and an abuse of discretion" and "violates federal law, including, but not limited to, the Constitution, the Communications Act of 1934, as amended, and FCC regulations promulgated thereunder."

You may recall that this same group sued the FCC over the net neutrality rules last month. That was done just in case the 10-day deadline could be applied after the rules were posted to the FCC's website, which happened before publication to the Federal Register. In either case, the initial challenge is mostly a procedural matter; detailed briefs laying out a legal argument against the FCC's rules will probably come this summer.

The FCC's vote reclassified fixed and mobile broadband providers as common carriers and imposed rules against blocking or throttling Internet content and a ban on prioritizing content in exchange for payment.

USTelecom represents both large and small service providers and suppliers for the telecom industry. AT&T, Verizon, and numerous other companies serve on its board of directors.

While Verizon sued the FCC over its 2010 net neutrality rules (and ultimately won), this time the legal challenges are expected to be led by consortiums rather than individual companies.

The National Cable & Telecommunications Association, the top group representing cable companies, declined to comment today on whether it plans a lawsuit.