Pick up almost any small electronic device and you will eventually find the same sentence, printed on the back, etched into a battery compartment, or buried in an on-screen regulatory menu: "This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions..." The phrasing is identical across products from unrelated manufacturers because none of them wrote it. It is regulatory boilerplate, reproduced verbatim from the Code of Federal Regulations, and the rule that requires it is 47 CFR 15.19.

Section 15.19 is titled "Labeling requirements," and paragraph (a)(3) is the one that produces the ubiquitous statement. It applies to devices that are not associated with a licensed radio service and are not cable input selector switches — which is to say, the vast majority of consumer gadgets. The rule mandates this exact text:

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.— 47 CFR § 15.19(a)(3), source

The rule frames this as a statement to be borne "in a conspicuous location on the device." That is why the language turns up physically on hardware rather than only in a manual. The two conditions are not marketing copy or a liability disclaimer of the manufacturer's own design; they are a compressed restatement of the operating bargain that Part 15 strikes for every unlicensed radiator. Condition one is an obligation the device owes outward: it may not cause harmful interference to other users of the spectrum. Condition two is a waiver the owner accepts: the device must tolerate whatever interference reaches it, even if that interference makes the device misbehave.

The same idea, two places in the rules

The two-conditions label restates, in consumer-facing form, the deeper requirement in 47 CFR 15.5 that no harmful interference be caused and that interference be accepted. The labeling rule's job is to put that bargain in front of the user at the point of the device itself. Section 15.19(a)(4) handles multi-part products, providing that where a device is built in two or more sections connected by wires and marketed together, the statement need only be affixed to the main control unit — which is why a wireless keyboard's dongle and the keyboard itself may not each carry the full text.

There is a closely related obligation that lives one section over and is frequently confused with the label. Section 15.105, "Information to the user," requires a separate interference notice to appear in the instruction manual of digital devices. For a Class A digital device — equipment for commercial or industrial use — 15.105(a) requires a notice stating that the equipment "has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules," that those limits are designed to provide reasonable protection against harmful interference "when the equipment is operated in a commercial environment," and that the device "generates, uses, and can radiate radio frequency energy" and may cause harmful interference if not installed and used per the manual. A parallel paragraph covers Class B devices — the residential category that most consumer products fall into — with a notice tuned to a home environment and guidance on steps a user can take if interference occurs.

Why two separate notices exist

The split is deliberate. The 15.19 label is short, fixed, and physical: it travels with the device and states the operating conditions in two sentences. The 15.105 manual notice is longer, environment-specific (Class A versus Class B), and instructional: it tells the user what the compliance testing covered and what to do if the device interferes with a radio or television. Together they form the visible surface of Part 15 compliance — the part of the regulatory regime a buyer actually encounters.

None of this language is optional or paraphrasable at a manufacturer's discretion. Because 15.19(a)(3) prescribes the wording, a device that altered or omitted the statement would fall out of compliance with the labeling rule even if the underlying hardware met every emission limit. That is the quiet reason the sentence is everywhere and always identical: it is not a sentence a company chose to write, but a sentence the rule requires it to copy. The next time the phrase "subject to the following two conditions" appears on a gadget, it is reading a line of federal regulation back to you — condition one, the device must not interfere; condition two, the device must put up with interference — the entire unlicensed-spectrum compact in twenty-odd words.

e-labeling and where the statement lives now

For decades the 15.19 statement lived physically — silk-screened onto a back panel or molded into a battery compartment. As devices shrank, the question of where to put a fixed block of regulatory text became real, and the rules accommodated electronic display of the required information. On many modern products the compliance statement and any FCC ID now appear in an on-screen regulatory or legal menu rather than on the exterior, while the labeling rule's substance — the verbatim two-conditions text in a location the user can find — is preserved. The migration from a printed label to a software menu changes the surface, not the obligation: the same 15.19(a)(3) wording must still be reproducible and accessible, which is why a phone's "regulatory information" screen reads like the back of an old device.

The two notices also map onto the two authorization paths in a way worth noting. The 15.19 statement attaches to devices subject to certification or to the Supplier's Declaration of Conformity — the two procedures that cover the bulk of consumer electronics. The 15.105 manual notice keys on whether the device is a Class A or Class B digital device, a distinction about the environment the equipment was tested for rather than about how it was authorized. A residential gadget carries the Class B language; a device intended for a commercial or industrial setting carries the Class A language quoted above. Reading both notices together tells a buyer two things at once: that the device met Part 15's operating conditions, and which use environment its emissions were measured against. Neither is the manufacturer's prose; both are the rule's, copied onto the product so the operating bargain travels with the hardware.