A more thorough explanation:

Nautae, caupones, and stabularii were groups of people in ancient Rome who were responsible for transporting goods by sea, running inns, and providing stables for horses. If someone entrusted their goods to them for safekeeping, these groups were held liable for any damages that occurred. They were also responsible for the actions of their employees and slaves. For example, if a traveler stayed at an inn and their belongings were stolen, the innkeeper would be responsible for compensating the traveler for their loss. This rule was so important that it was even adopted into the law of Scotland.