1  It is the joint and several duty of each parent to provide for the maintenance, protection, and education of his child until the child reaches the age of majority, except to the extent that the duty of one parent is otherwise or further defined by court order.Note: OCGA 19-6-15, the Uniform Child Support Guidelines, provides that child support shall be determined under the guidelines, but may be adjusted up or down based upon "a written finding of special circumstances."The special circumstances may be any factor which the trier of fact deems to be required by the ends of justice. Some of the factors which may warrant such varia-

2  (a) In all proceedings under this article between parents it shall be expressly permissible for the parents of a minor child to present to the court an agreement respecting any and all issues concerning custody of the minor child. As used in this Code section, the term "custody" shall not include payment of child support.

3  (2) "Joint legal custody" means both parents have equal rights and responsibilities for major decisions concerning the child, including the child's education, health care. and religious training; provided, however, that the court may designate one parent to have sole power to make certain decisions while both parents retain equal rights and responsibilities for other decisions.