Couples often develop their own communication style when they have been together for a while, and this includes a set of ground rules. Those who are at the beginning of a relationship will need to work out their own basic set of rules, and they will add to them as the relationship progresses. These are not a way to limit a partner, but they are a way for the couple to work out certain events before they occur. Doing this avoids misunderstandings and mistakes that may damage the relationship.
There are people who believe following any rules is not something they need to do, and this often ruins a relationship. If they continue to go outside the boundaries they agreed to with their partner, they are inflicting emotional pain. A person who holds this set of values can be left at any time, and it is important for their partner to recognize the fact they may never choose to change.