These are general laws under the High Kings code of law. The Merchant Cities have some autonomy and often have an interpreted value that creates loop holes.
It is forbidden to own people as property. Indentured servitude is allowed but must use a standards driven contract; Generally it is seen and used more as “sponsorship”. Debtor collective farms exist, though not as a ‘prison’ in the strict sense. The World Watchers and Guild of Solars (and House Malor in Dunstrand) assists in the overhead and administration of the justice system.