May a baptized Christian be a sponsor at the baptism of a child? How is this recorded?

A baptized Christian may not be a sponsor (godparent); however, he or she may be present at the baptism of a child as a Christian witness as long as there is a Catholic who is present and acting as the sponsor (godparent). In addition, if the catholic sponsor is male, the Christian witness must be a female; and if the catholic sponsor is female, the Christian witness must be male.

The name of the Christian witness is recorded in the Baptismal register followed by the words "Christian witness". The name is also placed on the Baptism certificate with the same notation.