Q (kú), the sixteenth letter, was in old vellums chiefly or only used in the digraph qu, perhaps under the influence of the Latin; it was afterwards disused in MSS. of the 15th century, but was reintroduced in printing (even Björn Halldórsson’s Dict. has a special Qu), until of late it has been discarded, and k is used throughout. All words beginning with Qu are therefore to be sought for under k.