It is correct for a clansman to wear his Chief's crest encircled within a strap and buckle bearing the motto or slogan.
The strap and buckle is the sign of the clansman, and he demonstrates his membership of his Chief's clan by wearing his Chief's crest within it, where it would be wrong to wear the crest alone.
If you have ever wondered about this badge and what it really means - Click here.
Unlike heraldry, tartan cloth has not been covered by statute either in use or design since the Proscription Act (1747 until 1782).
The Chief's Arms are strictly personal and are not the property of his family or clan.
The precedent set by “a tartan for every name” during the early 19th century has led to a popular attribution of specific tartans to specific clans. In the case of Donnachaidh, there are two unique patterns that were in use by the Clan before 1800, the Red Robertson and Hunting Robertson.
If anyone seeks to have their own version of the arms, in appropriate circumstances, they must by Scottish Law “difference” them from the Chief's arms and register them with the Lyon Register.