These are the 4 sins that a baptised Sikh must never commit. Once a Sikh has been baptised thru the Khande-da-Pahul he must abstain from the following:

1) Committing adultery
2) Consuming intoxicants, including alcohol, tobacco and drugs
3) Removing hair from any part of his body
4) Eating meat that has been religiously prepared, i.e. kosher meat, halal meat.