When someone says “Vow of Poverty” what do they mean? How much can a monk own besides clothing?
It depends on the order to which he belongs.
When a religious - monk or nun - makes a vow of poverty, that means that they own no personal property. They own nothing, not even their clothing. All the property in a religious community is owned by the community, the individual members have claim to none of it. When they need something like clothes or a book or a rosary, it is distributed to them if it is available. But they can’t think of themselves as owning it. Whenever it is called upon them to return it, they immediately give it back without any thought of thinking that it is their own.
I hope that clears it up some.
there are also some orders that allow certain members, after due discernment and spiritual director to take even more extreme vows of poverty, such as not to carry money at all or do any business transactions. In such orders (and it is become rarer these days) only some designated members under ordinary vows handle bills, accounting, taxes, purchasing and other business affairs. Some orders (and this is also becoming rarer) allow some members to live a lifestyle that is essentially begging, eating and using only what is donated. But no monk can do this on his own initiative, it has to be with permission of his superiors.
As others have responded, it depends on the charism of each particular community. Besides the more stringent observances of poverty noted above, other communities do permit their members to own some personal property, but the purpose of all observances of monastic or evangelical poverty is to cultivate a detatchment to worldly goods.
Whatever his orders “vow of poverty” allows him to have. It would vary from Religious Order to Religious Order.
As said above, it depends. But in all religious orders, the members do not, unless with special permission, have the use of whatever they own. And anything they earn, while being members, goes to the community.
So if you give Fr. Francis a watch or an electric shaver, he has to go to his Superior to ask permission to keep it. The Superior’s duty is to see to it that all members are, within reason, treated alike. So they will usually allow them to keep such minor items. But gifts of money, especially if substantial, would usually go into community coffers.
Related to this is the fact that a community cannot expel one of its members for health or other reasons, except extreme bad behavior as defined by canon law. What I mean is that the state of poverty that religious observe also has it earthly advantages.