For a lot of things you need permission of the parents or the guardian, when working with minors. For example to collect their data, to take pictures, to go abroad with your group, ... It is a good idea to always ask for a written permission of the parents when doing something special such as a weekend away. A template (Dutch) for the permission of pictures and video material you can find below:
Besides permission, it is useful (but not obliged) to ask for a medical record. When something would happen, you always possess the correct medical information to provide to first aid responders. Attention! You can only keep a medical record for one year, afterwards you are obligated to destroy it. A template in Dutch below.
In Belgium there is a ban on child labor for children under 15 years old. Activities that fit in with the education or upbringing of children are not included here.
Although most theatre organizations fall under leisure activities and education for the child, and therefore do not have a ban, it does not hurt to read the rules for child labor. For different age categories, different durations are proposed, guidelines that every association working with children could take into account.
A new rule may be introduced in the autumn of 2022 whereby people who work with young people (entertainers, supervisors, teachers, etc.) will have to be able to submit an extract from the criminal record.