New Testament manuscripts in Greek are categorized into five groups, according to a scheme introduced in 1981 by Kurt and Barbara Aland in The Text of the New Testament. The categories are based on how each manuscript relates to the various text-types. Generally speaking, earlier Alexandrian manuscripts are category I, while later Byzantine manuscripts are category V. Aland's method involved considering 1000 passages where the Byzantine text differs from non-Byzantine text. The Alands did not select their 1000 readings from all of the NT books; for example, none were drawn from Matthew and Luke.

Description of categories

The Alands' categories do not simply correspond to the text-types; all they do is demonstrate the 'Byzantine-ness' of a particular text; that is, how much it is similar to the Byzantine text-type, from least (Category I) to most similar (Category V). Category V can be equated with the Byzantine text-type, but the other categories are not necessarily representative of a text-type. Even though most texts in Category I agree with the Alexandrian text-type, they are not necessarily Alexandrian themselves; they are just very non-Byzantine. The Alands introduced the following categories (Aland & Aland category description according to the 1989 English translation, p. 106, between quotation marks):

Distribution of Greek manuscripts by century and category

The following table is derived from the Alands' The Text of the New Testament.

Number of manuscripts by century and category

Limitations

This system of classification would seem to prefer manuscripts which coincide more or less with the critical text of the Nestle-Aland and UBS Greek New Testaments, of which there are many supposedly Alexandrian manuscripts in Category I. Some manuscripts are placed in Category V because they are considered too "brief" to classify. The Alands consider Uncial 055 unclassifiable because it is a commentary, and not exactly an "Uncial" manuscript. Accordingly, , Uncial 080, Uncial 0100, Uncial 0118, 0174, 0230, 0263, 0264, 0267, 0268 are considered by the Alands to be too brief to classify. Uncial 0144 and 0196 are not accessible. The Alands do not classify, stating this is due to the Diatessaric character of text (i.e. the four Gospels combined into a single narrative). was classified to Category I, but it is not a representative of the Alexandrian text-type. According to biblical scholar Philip Comfort it is "a good example of what Kurt and Barbara Aland call "normal" (i.e. a relatively accurate text manifesting a normal amount of error and idiosyncrasy). The Alands references are one of the most widely used references for New Testament textual criticism in theological studies today along with the UBS and continues to receive regular updates as more manuscripts are found and become available for study. Published apparatus are constrained by limitations of space. Furthermore, updates do not happen in real time although efforts have made rapid progress in bringing the data online allowing for a more real-time access to research and discussion in ways no other text from antiquity has ever been done with the scale and scope of evidentiary materials. Originally, Waltz stated: "As a classification scheme, [Aland & Aland's] attempt was at once a success and a failure. A success, in that it has conveniently gathered data about how Byzantine the various manuscripts are. A failure, because it has not been widely adopted, and in any case does not succeed in moving beyond Byzantine/non-Byzantine classification."