It carries the symbols of its history, culture and religion. It was granted in 1511 by Ferdinand of Aragon, then king of Aragon and regent of Castile in the name of its daughter the queen Juana, incapacitated. However, until 9 March 1905, the law regulating the Puerto Rico coat of arms was not approved. After several investigations and amendments to the law to obtain the interpretation of the shield, in 1976 the current version is approved. In field of sinople, appears a lamb (Agnus Dei, lamb of God) on a book from which the seven seals described in the Apocalypse stand out. This is a common heraldic symbol to symbolize St. John. To the main field is surrounded by a border consisting of 16 pieces that alternate in representation of 4 entities:
First, in the field of gules, a golden castle, representing Castile.Secondly, in the field of silver, a lion, whose most correct representation is of scarlet purple, although also customary to show itself in gules, and symbolizes the Kingdom of Leon (that next to Castile conformed the Crown of Castile).
The following position shows a flag, whose original reference of the Royal Decree of 1511 does not specify. Some representations show a flag with quarters of Leon and Castile, while others show another one with the quarters of Aragon and Sicilia, by Corona of Aragon, in order to be able to complement the previous reference to the Crown of Castile.
The last series of compons shows the cross of Jerusalem, which is of gold on a silver field and symbol of the Kingdom of Jerusalem, intended by King Ferdinand the Catholic through its Neapolitan heritage.
On the head is a royal crown, open, as a sign of the authority and jurisdiction of those who granted the shield in 1511. In the left part appears the initial "F" of Fernando the Catholic, king of Aragon and Sicily, and to the right "Y" of Yoanna I, that is, Juana I of Castile. It is a very common mistake to believe that Y represents Ysabel I, that is, Isabel I, but since she died in 1504, she obviously could not have anything to do with this shield. His daughter Juana succeeded her as queen of Castile and Leon, and continued to wear the monogram Y and yoke. Under the initials appear the yoke and the arrows, also personal symbols of the Catholic Kings; However, contrary to another common error, there is no evidence to suggest that the use of initials, arrows and yoke was intended to symbolize that Puerto Rico was discovered during the reign of Ferdinand and Isabella. At the tip is inscribed in Latin the motto "Joannes Est Nomen Ejus" which means "John is his name", a quote from the Gospel Vulgate according to Luke (1:63).