There are nine family surnames (Affleck, Byres, Cobb, Crawford, Deuchar, Downie, Fotheringham, Rhind & Summers) that are officially allied with the Lindsay surname. For many of these surnames, this relationship originates back to the earliest times that the Lindsays established a presence in England and Scotland.
The authority that is used by several of the Clan Lindsay Societies around the world, for establishing this official list of allied family surname links, is Scots Kith & Kin, HarperCollins Publishers, Glasgow. With exception, the Clan Lindsay Society of Scotland only accepts into membership those of the Lindsay (how ever spelled) surname and those whose Lindsay heritage is no more than three generations removed from the Lindsay surname.
From the Scots Kith & Kin, referenced volume, are the following surnames that are officially recognized as affiliated with the Clan Lindsay surname.
The Clan Lindsay Association USA has adopted one addition to this list by including the Affleck surname due to the fact the Afflecks/Auchinlecks were the hereditary armor bearers for the Earls of Crawford.
As with the Lindsay surname, there are multiple accepted spellings of each of these nine great surnames.