variant location
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.
(Colwell et al. 1964, 254)