The Rooklooster Register is a paper manuscript, containing II + 439 folia: modern foliation in Roman numerals and a modern foliation in Arabic numbers; original Roman numerals restarting in each of the three parts of the codex. The codex is written in a littera cursiva, with the exception of the rubrics and the running titles, which are in a littera hybrida. The leaves measure 288x210 mm, while the written space roughly measures 203x118 mm.
The original brown calf leather binding over wooden boards has the same decorations on the front and the back. Around a central lozenge pattern, consisting of threefold fillets, the covers are divided into compartments by horizontally and vertically crossing ditto fillets.
The stamp decorations within the lozenges consist of lozenge foliage around a star-shaped pattern, while those within the compartments show stamps of rosettes, heraldic lilies and geometric shapes around a central point; the geometric shapes are also found on the contact points of the lozenges. Underneath the lozenge pattern on the front cover, there is a stamp with the sixteenth-century caption roedencloester.
The spine cover and its joints clearly were restored, probably in February 1923, according to a note on fol. Ir° . The remains of two fastenings have more recently been renewed with hook fastenings. The back displays five raised bands. Three eighteenth-century labels of different sizes are glued on the back.
The first one, in between the top and the first raised band is a little square-shaped label with the caption R.C. | 87 ("Rouge Cloître" and the serial number of the manuscript), written in the Chambre Héraldique by Beydaels de Zittaert. The second label, in between the first and second raised band, is a large rectangular label with the caption Catalogus | Illust. Scriptor. In between the fifth raised band and the tail, there is a third, square-shaped label showing the Arabic number 8. On the inside the covers are decorated with nineteenth-century agate paper (marbled paper with a cloud pattern). On the inside of the front cover there are labels with book numbers; on the top left 310 followed by 308 (both numbers are crossed out) | S.N. 12694 (the current shelf mark) and on the bottom left 9373 (the reference number of the manuscript in the personal library of the emperor).
The text decorations are sober: red and black paragraph marks, guide letters, red initials (four to six lines high), red lombard letters (two to four lines high), with some decoration.