102 “does not differentiate in treatment of traffic, or if it differentiates in treatment of traffic without reference to the content, application, or device.” Id. at 5663 ¶ 144 n.344. Many of the paragraphs in that section of the Order also specifically identify the kind of conduct that would violate the Rule. The Commission explains, for example, that “unfair or deceptive billing practices, as well as practices that fail to protect the confidentiality of end users’ proprietary information, will be unlawful.” Id. at 5662 ¶ 141. It goes on to emphasize that the “rule is intended to include protection against fraudulent practices such as ‘cramming’ and ‘slamming.’” Id. And “[a]pplication-specific network practices,” including “those applied to traffic that has a particular source or destination, that is generated by a particular application . . . , [or] that uses a particular application- or transport- layer protocol,” would trigger concern as well. Id. at 5663 ¶ 144 n.344. Given that “we can never expect mathematical certainty from our language,” those sorts of descriptions suffice to provide fair warning as to the type of conduct prohibited by the General Conduct Rule. Grayned v. City of Rockford, 408 U.S. 104, 110 (1972). To be sure, as a multifactor standard applied on a case-by-case basis, a certain degree of uncertainty inheres in the structure of the General Conduct Rule. But a regulation is not impermissibly vague because it is “marked by flexibility and reasonable breadth, rather than meticulous specificity.” Id. (internal quotation marks omitted). Fair notice in these circumstances demands “no more than a reasonable degree of certainty.” Throckmorton v. National Transportation Safety Board, 963 F.2d 441, 444 (D.C. Cir. 1992) (internal quotation marks omitted). We are mindful, moreover, that “by requiring regulations to be too specific courts would be opening up large loopholes allowing conduct which should be regulated to escape regulation.”