Example, 5 days ago. The referee used the verbiage "Unsportsmanlike conduct"

That can be a violation of any of the following rules under Rule 9 Section 2

Unsportsmanlike Acts
Unfair Tactics
Unfair Acts
Contacting an official


Look at Appendix F with all the official signals, then look at Appendix G summary of penalties. . .
Unfair acts is Signaled by signing or stating "Unsportsmanlike Conduct".


Here is the exact rule, (Note- The Penalty is signaled "Unsportsmanlike Conduct")

Unfair Acts
ARTICLE 3. The following are unfair acts:
a. A team refuses to play within two minutes after ordered to do so by the
referee.
b. A team repeatedly commits fouls for which penalties can be enforced only
by halving the distance to its goal line.
c. An obviously unfair act not specifically covered by the rules occurs during
the game. This includes substitutes, coaches or any other persons subject to
the rules, other than a player or official, interfering in any way with the ball
or a player while the ball is in play (A.R. 4-2-1-II, 9-2-3-I and 9-2-3-IV).
PENALTY— Unsportsmanlike conduct. The referee may take any action
they consider equitable, which includes directing that the
down be repeated, including assessing a 15-yard penalty,
awarding a score, or suspending or forfeiting the game [S27].