Coat of arms of the U.S. Archbishop George Hugh Niederauer, Archbishop Emeritus of San Francisco.
The coat of arms of an archbishop consist of the shield placed upon the archiepiscopal cross. This cross, used only by an archbishop, has a smaller bar above the cross bar which supports the crucified Christ. The origin of this smaller bar lies in the representation of the small plaque, on which was written the inscription I.N.R.I. for Iesus Nazarenus Rex Iudaeorum (Jesus of Nazareth, King of the Jews). The use of this type of cross as the insignia of the metropolitan archbishop dates back to 1232 under Pope Gregory IX. This cross is the primary symbol of the rank of archbishop.
This shield is divided in two in a heraldic device called marshalling, or the combining of two coats of arms. On the left side, we see the insignia of the Archdiocese of San Francisco. The crossed arms of Christ and St. Francis of Assisi are a classical representation of St. Francis.
On the right, Archbishop Niederauer’s personal coat of arms shows, on a white field, a red cross known in heraldry as the “Cross of Saint George.” This cross, as well as the black abbot’s crozier representing Saint Hugh of Cluny, signify Archbishop Niederauer’s baptismal patrons. The wavy green base of the field alludes to the rolling hills and valleys of a “low meadow,” a translation of the bishop’s surname of “Niederauer.”
At the upper left of the bishop’s personal coat of arms are two angel wings in blue to recognize Los Angeles, the city of Our Lady of the Angels, where Archbishop Niederauer was born and served as priest. The rose shown between the angel wings signifies Mary, the mother of Jesus, as the Mystical Rose, Queen of the Angels.
On the scroll beneath the field is a motto derived from the Gospels of Saint Mark (10:45) and Saint Matthew (20:28): “To Serve and To Give.” This motto expresses Archbishop Niederauer’s desire to emulate Christ who “did not come to be served but to serve and to give his life as a ransom for many.”
Above the cross is a type of hat called a galero with two tassels or fiocchi on the brim and ten suspended on each side from cords. The galero is no longer worn, but is still utilized in the arms of cardinals, patriarchs, archbishops and bishops. A red galero is the traditional symbol of a cardinal, hence the saying “receiving the red hat.” The appropriate color for the galero of a patriarch, archbishop or bishop is green. The number of tassels also is a symbol of rank. Cardinals have fifteen red tassels, patriarchs have fifteen green tassels, archbishops ten green and bishops six. 
Reference:

www.sfarchdiocese.org
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