Article 13 reads:
"Whereas the Queen of Great Britain has continually pressed and insisted with the greatest Earnestness, that all the Inhabitants of the Principality of Catalonia, of whatever State or Condition they may be, should not only obtain a full and perpetual Oblivion of all that was done in the late War, and enjoy the entire possession of all their Estates and Honours; but should also have their ancient Privileges preserved safe and untouched; the Katholic King, in compliance with the said Queen of Great Britain, hereby grats and confirms to all the Inhabitants of Catalonia whatsoever, not only the Amnesty desired, together with the full Possession of all their Estates and Honours; but also gives and grants to them, all the Privileges which the inhabitants of both Castiles, who of all the Spaniards are the most dear to the Catholick King, have and enjoy, or may hereafter have and enjoy".
This text was signed in Utrecht on July 13 1713. (source)
King Philip V of Spain (IV of Aragon) laid siege to the city of Barcelona on July 25 1713: twelve days later. The siege was to last 13 months, and ended with the fall of the city to the Spanish and French troops.
Britain's signature in the Treaty of Utrecht broke with its commitments in the earlier, secret Treaty of Genoa, signed between England (represented by Mr. Mitford Crow) and Catalonia ( represented by Antoni Peguera i Aymerich and Dr. Domènec Perera) in 1705. A Spanish version can be read here (pp. 43-47 of the book, pp. 99-103 of the PDF file). A Catalan translation is available here.