A unit-of-variation or a variation-unit could be described in terms of that passage or section of the Greek NT where our MSS do not agree as to what the Greek text is. By variation-unit we do not mean an individual variant reading in a particular MS. Rather we are referring to a length of the text wherein our MSS present at least two variant forms; it is that passage in which differences occur.
On nomme lieu variant tout passage d’une oeuvre où l’un au moins des manuscrits qui l’attestent présente une différence de texte par rapport aux autres. Le lieu variant correspond, dans une certaine mesure, à ce qu’est l’unité critique dans l’apparat de l’édition.
A variant location is a locus in the text where at least two concurrent readings exist. A variant location can consist in one word or more than one word: an omission of several words, for example, is considered as a single variant, not as a concatenation of omissions of individual words, which would not make sense according to the way mistakes in copying are normally committed.