In this instance, simply used as short-hand description of collections of case reports/case notes which found their way in print or were deliberately published in print independently from the work of the Selden Society or Ames Foundation.
For law before the mid eighteenth century
Viner's General Abridgment of Law and Equity (23 volumes, 1741-1753)
is the best starting point.
Viner's precursors who, though of lesser rank, may nonetheless be useful are:
Sheppard's Epitome (1656)
Sheppard's Grand Abridgment (1675)
Hughes's Grand Abridgment of the law (1660-63)
Rolle's Abridgment des plusieurs cases (1668)
For the law after Viner try
Comyn's Digest (1760s)
Bacon's New Abridgment (1763-66)
By convention, collections of cases and case notes from the early modern/Tudor period onwards are referred to as law reports - their medieval counterparts are called year-books.
One new feature was that the printers producing them liked to embellish the title pages of their products with the names of famous laywers or judges. But there was no control over quality : many of the early collections are clearly falsely attributed. However, this publishing practice means they are referred to as the Nominate Reports.
Prior to 1700 only three sets of reports were actually published by their authors Plowden’s Commentaries (ER 75 KB 1550-1580), Coke’s Reports (ER 76-77 KB 1572-1616) and Bulstrode’s Reports (ER 80-81 KB 1610-1625).
It was not until the 1750s that reporting standards improved.
The LawBod has the Nominate Reports at Cw UK 100, but we suggest you use the English Reports to read the text. The English Reports reprinted all the major Nominate reports published before 1865. They can be found at Cw UK 120 E50 or via a number of online databases, please see the links below. EEBO provides e-facsimiles of the original publications.
In 1865 the foundation of the Council of Law Reporting (later the Incorporated Council) ushered in the modern age. The Council is the publisher of The Law Reports (AC, KB/QB. Ch, etc) which became and remain the most authoritative law reports.
The editors of the Selden Society are doing much to add to our understanding of the period of pre-Victorian by publishing manuscripts which had previously escaped the printing presses.