"P0" means: Priority Zero — the most-urgent possible bug or task. Drops everything; whoever is on it has authority to break process to fix it. Some comp.... This is a fairly neutral word with no inherent risk attached. There is no real cause for parental concern; it is descriptive vocabulary rather than something dangerous. If your child uses it, context will usually make the meaning clear. A brief, curious question about where they heard it is generally enough to know whether to follow up.