What are the libero rules at U16, U17 and U18?

Volleyball Canada 2026-27 rulebook, rule 19:

• Number: 16U and 17U may use only one libero per set; 18U may use up to two per set (14U and 15U may not use a libero). Only one libero may be on court at a time.
• Re-designation: the libero may be re-designated after each set. The libero's number must be on the line-up sheet for each set. If the coach changes the libero between sets, the new libero may be any player registered on the score sheet, wearing the number recorded for them, and the replaced libero can play as a regular player in the correct uniform.
• Score sheet: in Volleyball Canada play the libero is recorded with the team roster, not on the special line.
• Uniform: the libero must wear a uniform with a different dominant colour from any dominant colour of the team jersey, numbered like the rest of the team.
• Back row only: the libero may replace any back-row player, may not serve, block or attempt to block, and may not complete an attack hit from anywhere if the ball is entirely higher than the top of the net. A player may not attack a ball entirely higher than the net that comes from an overhand finger pass by the libero in the libero's front zone.
• Replacements: libero replacements are unlimited and do not count as substitutions, but there must be a completed rally between two libero replacements (with limited exceptions). They happen through the Libero Replacement Zone while the ball is out of play and before the service whistle. At the start of a set the libero cannot enter until the second referee has checked the line-up and authorised the replacement.