About 1306 Irish secular clergyman, writer, anthologist and indexer Thomas of Ireland (Thomas Hibernicus), working in Paris, completed the first manuscript of his Manipulus florum, a florilegium or collection of authoritative quotations. A graduate of the Sorbonne, Thomas compiled his anthology from the library of the Sorbonne, which was at the time, the largest library in Christendom.
Thomas's Manipulus florum was among the mostly widely used florilegia in the Middle Ages, and it remained extensively useful through at least the seventeenth century. The text survives in over one hundred eighty manuscripts. It was first printed in Piacenza by Jacobus de Tyela, and issued on September 5, 1483. (ISTC No.ih00149000). During the 16th century it was printed twenty-six times, and there were eleven printed ediitions in the seventeenth century. Altogether there were at least fifty editions of the work printed between 1483 and 1887. In November 2013 a digital facsimile of the 1483 edition was available from the Bayerisches Staatsbibliothek at this link.
Probably the Manipulus florum was so extensively used because of its advanced system of indexing and cross-references:
"Thomas organized the 'flowers' that he gathered for this collection under 266 alphabetically-ordered topics, from Abstinencia to Christus (Christus coming at the end in the manuscripts and the earliest print editions because the Greek letters Χρσ are used for the abbreviation). He also assigned unique reference letters to the individual entries under each topic, doubling the letters when the number of entries for a given topic exceeded 23 (i.e. the number of letters in the Latin alphabet) entries. For example, Vsura b is the second (and last) entry under the shortest topic; because Prudencia siue prouidencia has 24 entries, the twenty-third entry is designated z and the last one is ba; and Mors di is the last entry under the largest topic, with 97 entries. As Thomas explains in his Preface, these reference letters were created to support his cross-referencing system; at the end of nearly all of the topics he provided a list which includes similar topics (essentially synonyms and antonyms, such as Temperancia and Gula which are cross-referenced at the end of Abstinencia) and, more usefully, specific entries of related interest under unrelated topics. According to Mary Rouse and Richard Rouse, this combination of an alphabetized subject listing and a cross-referencing system represents the cutting edge of information technology at the time of its compilation. They also noted the remarkable stability of the manuscript tradition, which is partly due to the reproduction of the text by the Paris stationers' companies using the pecia system" (http://web.wlu.ca/history/cnighman/page2.html, accessed 11-06-2013). The quotation is from Chris L. Nighman's major online reference, the Electronic Manipulus florum Project.
Rouse & Rouse, Preachers, Florilegia and Sermons: Studies on the Manipulus Florum of Thomas of Ireland. PIMS Texts and Studies 47, Toronto (1979).