Uniform Information

Rule 4.3.3.2 page XV states:
Due to visibility issues, minimum number sizes have been revised. The numbers must be a minimum of 4” in height on the chest and a minimum of 6” in height on the back. It is recommended that the numbers be a minimum of 6” in height on the chest and a minimum of 8” on the back

Uniform numbers centered on the chest and on the back.
Uniform numbers 6 inches on the chest and 8 inches on the back.

 

 

As for the Libero's uniform, sometimes (most cases) it's what the rules DON'T say, not what they do say.  You referenced Rule 4.3.1, which basically says the uniforms need to be identical for the team EXCEPT FOR THE LIBERO and USAV 4.3.1 states this further. Since the Libero is exempt from this rule, it applies to the entire uniform.  It's required to have a contrasting jersey, and the shorts may or may not be different from the rest of the team.

Rule 19.2 says the Libero's jersey (at least) must contrast to the rest of the team. That means the jersey is required to contrast, and the rest of the uniform may or may not.