The local records of medieval Yarmouth are focused on a fine series of court rolls; unfortunately these do not extend a great deal beyond coverage of judicial matters (albeit broadly interpreted), although in mid-fifteenth century they diversified a little to include accounts of borough revenues. There is no extant medieval custumal, nor any volume compiling local by-laws until the Book of Oaths and Ordinances (Yarmouth C18/1) begun in the Tudor period.
That book of memoranda, or reference manual for one or more Corporation officials, may have been the personal initiative of Thomas Banyard, the borough steward (legal advisor) or town clerk offices that appears to have been combined at this period who would go on to serve as a bailiff of the borough (1506). A number of similar books were produced in English towns thanks to the efforts of such individuals. Or it was one manifestation of what was an active period of administrative reform during the first half of the 1490s. The latter interpretation is supported by an entry in the chamberlains' account for 1491/92, being a payment for the compilation of such a book.
This retrospective compilation incorporates not only the reforms of the year in which it was begun, but the texts of older documents recording ordinances promulgated at various times between 1272 and 1491. At the same time, effort was made to put down in writing what can surely only be a selection of long-standing customs of the borough, primarily (it appears) regarding judicial procedures concerning issues that may have been problematic for the courts; these, although possibly reworded or updated for the occasion, must to some degree reflect earlier practices. The ordinances of 1300 were copied from a now missing volume called the "Golden Book", which might have been a medieval custumal (but more probably was a book of general memoranda such as are found at Lynn, Ipswich and Colchester); we also hear of a Domesday Book, Little Red Book and Great Black Book, all of similarly unknown character.
The value of these bye-laws is, in part, that they reflect some of the preoccupations, concerns and issues related to borough government and society.