Child custody and legal guardianship are legal terms which are used to describe the legal and practical relationship between a parent or guardian and a child in that person's care, such as the right to make decisions on behalf of a child and the duty to care for and support the child. Following ratification of the United Nations Convention on the Rights of the Child in most countries, terms such as parental responsibility, "residence" and "contact" (also known as "visitation", "conservatorship" or "parenting time" in the United States) have superseded the concepts of "custody" and "access" in some member nations. Instead of a parent having "custody" of or "access" to a child, a child is now said to "reside" or have "contact" with a parent. Family law proceedings that involve issues of residence and contact often generate the most acrimonious disputes. While most parents cooperate when it comes to sharing their children and resort to mediation to settle a dispute, not all do. For those that engage in litigation, there seem to be few limits. Court filings quickly fill with mutual accusations by one parent against the other, including sexual, physical, and emotional abuse, brain-washing, parental alienation syndrome, sabotage, and manipulation. Custody battles are not in the child's best interest and are often used by an angry parent in order to control his/her former partner. In some places, courts and legal professionals are beginning to use the term parenting schedule instead of custody and visitation. The new terminology eliminates the distinction between custodial and noncustodial parents, and also attempts to build upon the best interests of the children by crafting schedules that meet the developmental needs of the children. For example, younger children need shorter, more frequent time with parents, whereas older children and teenagers may demand less frequent shifts yet longer blocks of time with each parent.