When a full-service station wants to change its channel, it first prepares a “Petition for Rule-Making,” which it submits to the FCC. The FCC needs to know a few things. First, it needs to provide full technical parameters of the proposed facility on the new channel. Second, it needs to provide an OET Bulletin No. 69 analysis using the FCC's TVStudy software, in order to demonstrate that it will not create excessive new interference to any other full-service or Class A station and otherwise complies with FCC rules. Third, it should sow that its proposed new facility's principal community contour will completely encompass its community of license. Finally, it should show that its new facility will not create more than a “de minimis” loss, which is defined by a 1980 precedent as 556 or fewer people.

Should the FCC determine that all of those criteria are met, it will issue a “Notice of Proposed Rule-Making” or “NPRM.” The petitioner is expected to submit comments affirming its desire to