The short answer is "no".
BTW, I take the word "official" in the context of something that would hold up in court based on fact rather then opinion.
Framing is not a regulated activity, there is no industry recognized standard, and the word "conservation" is subjective.
However, there are several different organizations who have defined various
levels* of conservation or preservation.
In order for any definition to be "official" you will have to be more specific than simply stating "conservation framing". For instance, you could say:
- "Framed according to Matting and Hinging of Works of Art on Paper as published by the Library of Congress", or
- "Framed to G.C.F. Conservation Level", or even
- "Framed to XYZ Frame Shop Conservation Standard" if you want to define it yourself.
*since "conservation" is subjective, that is, my definition may be different than yours, it's like asking what the official color of the sky is. Some people have defined it; in fact Benjamin Moore has several: Morning Sky Blue, Polar Sky, Mediterranean Sky and probably others. If you are a painter and someone asks you to paint a room Morning Sky Blue, but you use Polar Sky, you are unlikely to prevail in a court case against you because there is little room for interpretation. OTOH, someone asked you to paint their room "sky blue", you could pick just about any blue you wanted and there would be little chance of recourse.