Clan Gunn motto has no status
The Clan Gunn motto has no status as the Clan motto must be derived from the Clan Chief armorial bearings as agreed by Lord Lyon, and given Lord Lyon has never accepted a Clan Gunn Chief there are no armorial bearings from which a motto can be derived. See - http://clangunn.weebly.com/the-non-existent-clan-gunn-crest-badge-and-motto.html
The reason for this post is that I have just acquired a detailed heraldry text which further supports this idea as it says
'In Scotland the motto forms a definite part of the armorial bearings. It can only be borne by authority...'
Page 174, (revised by) C.W. Scott-Giles, Fitzalan Pursuivant of Arms Extraordinary, Boutell's Heraldry, 1958 Frederick Warne, London.