In a press conference Monday, heads of Google and Verizon reaffirmed their commitment to “an open Internet,” so-called net neutrality, a concept holds that Internet service providers (ISPs) ought to treat

all online properties the same. In other words, users can access

Fastcompany.com as quickly as the BBC, or Facebook as fast as

Twitter–the sites receive no preferential treatment based on their

popularity or content.

There were major caveats, though.

Google and Verizon released a seven-part joint proposal to lawmakers that stressed that wireline Internet (non-wireless broadband) users should have “access to all legal content on the Internet” without discrimination. This “nondiscrimination” policy bans all prioritization (including paid prioritization) of Internet traffic. “In addition to not blocking or degrading of Internet content and applications, wireline broadband providers also could not favor particular Internet traffic over other traffic,” states the proposal.

“Under the principles, there is no prioritization of traffic that comes from Google over the Internet, period,” said Verizon CEO Ivan Seidenberg today, point-blank. The companies also asked for FCC regulation in this regard, proposing that violators of the policy should be penalized up to $2 million on a case-by-case basis.

But Google and Verizon also left room for broadband providers to “offer additional, differentiated online services, in addition to the Internet access and video services (such as Verizon’s FIOS TV) offered today” where ISPs could give preference to certain Web traffic. In other words, there is a loophole for new services to avoid net neutrality regulation. These services may include “health care monitoring, the smart grid, advanced educational services, or new entertainment and gaming options.” The proposal does promise FCC oversight in this area, and according to Google, was “not designed to circumvent the rules.”

The companies’ proposal also distinguishes between wireline and wireless providers, arguing that the principles do not apply to the latter. “We both recognize that wireless broadband is different from the traditional wireline world, in part because the mobile marketplace is more competitive and changing rapidly,” the policy reads. “In recognition of the still-nascent nature of the wireless broadband marketplace, under this proposal we would not now apply most of the wireline principles to wireless … The Government Accountability Office would be required to report to Congress annually on developments in the wireless broadband marketplace, and whether or not current policies are working to protect consumers.”