The vow of poverty is the common thing we know a priest takes. But not all priest are required to take a vow of poverty. To know more about this topic please check Catholic Encyclopedia or Catholic Exchange .
When I entered the seminary there were two form of training I went through as regards the vow of poverty. One we cannot keep or hold money in our pockets and the second we cannot keep food in our cabinets/drawers.
Yes, we cannot keep money as long as we are inside the seminary. This is for both practical and psychological purposes. The practical purpose is that we without money in our pockets cannot sneak out from the seminary. Without money one seminarian cannot go out to buy things or go see movie. Since we don't have money a seminarian relies only on what is given as part of our training inside the seminary.
Psychological purpose of this training is that it trains a seminarian self-restraint. We don't spend; we only eat what the seminary offers. Money has a power, the power to buy. Without it we are trained to be contented to what we have. Which is what the vow of poverty makes a priest. Money is not evil as most people quote from the Bible "Money is the root of evil" rather "The love of money is the root of all evil". Money is either good or evil depending on how a person uses it.
The second training is that we are not allowed to keep food in our cabinets or drawers. Thus the store room or what we call "Minas" room comes into the picture. Still part of self restraint, there is a place and time to eat. Having food within one's reach tempts one to just grab and eat. It is customary for parents to bring food for their seminarian sons. In order to avoid the temptation to eat all those food are stored in the Minas room and only opened on particular time. It is only on meals and snack time that it is open.
The vow of poverty is not something that says "you can't have this or that" it is a way of instilling discipline and training a person to prioritize on more important things by being contented.
