But dB without reference makes sense in many many occasions. Either because the reference is implicit (not ideal, but we have many implicit assumptions in communication), or because it's genuinely a ratio. Attenuation, gain.

If you every find an "official" written document that uses dB not as attenuation/gain and is not specifying the reference (at least in a footnote), it's written either by idiots or for idiots, or both.