Uniform Code of Military Justice (UCMJ)
ART. 88 - CONTEMPT TOWARD OFFICIALS
Any commissioned officer (italics mine) who uses contemptuous words against the President, the Vice President, Congress, the Secretary of Defense, the Secretary of a military department, the Secretary of Transportation, or the Governor or legislature of any State, Territory, Commonwealth, or possession in which he is on duty or present shall be punished as a court-martial may direct.
Yes that's true, good catch. I should have included Art 134. Of course, any enlisted man would be charged under with this specification for such a similar offense, as well as Art 92, for disobeying the DoD directive in this matter. But, the definition of "official" would be drawn from Art. 88, FWIW.
When the UCMJ was drafted after the conclusion of WWII (and it's predecessor, the Articles of War back during the Founding), I'm sure no one imagined an opportunity for an enlisted man or an NCO to show contempt towards an official, because an enlisted man or NCO would have virtually no interaction with an official. Of course, officers frequently would. Clearly, the internet and mass media has changed all that.
Art. 80, which specifies contemptuous behavior by enlisted men of the superiors does not include reference to the President or other civilian authorities, but it would be a mistake to read that as a license for enlisted men to make contemptuous remarks about the CIC, or other civilian leaders. DoD 1344.10, and several other directives codifies that contemptuous language by enlisted men is not permissible, FWIW.