How do false starts work for my young athletes?

Under 14 and Under 16 (UKA Rule TR16 S2), and all athletes in Open Graded races that U14s or U16s may enter, whether or not a start information system is used:

• Individual events: the first false start earns a warning (yellow and black card); an athlete responsible for two false starts is disqualified.
• Combined events: warning first; disqualification on the athlete's third false start.

Under 18 and older (World Athletics Rule TR16.8): except in combined events, any athlete responsible for a false start is disqualified (red and black card). In combined events, the first false start in a race warns everyone, and anyone making a further false start is disqualified.

What counts as a false start (TR16.7): after taking the final set position, commencing the start before the gun. In a crouch start, that's a hand or foot losing contact with the ground or blocks; in a standing start, a foot losing contact with the ground. Movements that don't break contact are not false starts, but delaying, not settling promptly or disturbing others can earn a warning for improper conduct, and a second such warning in the competition means disqualification.