In this case, the parties are referred to by the letters X and Y to prevent disclosure of their identity. This may be done to protect their privacy if disclosure of a name might cause undue embarrassment or harm. Cases involving children, or people with mental illness or disability, are also cited in this way for the same reason.

In this case, Y is a person, perhaps a child, who does not have the legal capacity to take action in his or her own right. The action is taken on Y's behalf by a tutor or guardian, appointed to look after Y's legal affairs.