Over the course of English history there were a number of acts of uniformity. All had the basic object of establishing some sort of religious orthodoxy within the English church.
The Act of Uniformity 1552 (5 and 6 Edward VI, c. 1) required the use of the Book of Common Prayer of 1552
The Act of Uniformity 1559, (1Eliz., c. 2) was adopted on the ascension of Elizabeth I. See Elizabethan Religious Settlement
The Act of Uniformity 1662, (13 and 14 Chas. II , c. 4) was enacted after the restoration of the monarchy. It required the use of all the rites and ceremonies in the Book of Common Prayer of 1662 in church services.
For more information, see Conventicle Act.
(The '16 Charles II c. 2' nomenclature is reference to the statute book of the numbered year of the reign of the named King in the stated chapter. This is the method used for Acts of Parliament from before 1962.)