Patronymic was used by illegitimate royal children who were acknowledged as such by their fathers. The use of "Mac" in some form was prevalent in Scottish Gaelic, Irish and Manx, in all of which it denotes "son". "Mc" is also a frequent anglicisation in both Scotland and Ireland. In Ireland, the forms "Mag" and "M'" are encountered. The prefix "Mac" is used to form a patronym, such as "Mac Coinnich" – or the anglicized 'Mackenzie' – son of Coinneach/Kenneth. The female equivalent of "Mac" is "Nic", condensed from "nighean mhic" (in Scottish Gaelic) or "iníon mhic" (in Irish), both meaning daughter.
Mac and Mc together dropped for some newer computer systems, and the interfiling of Mac and Mc names is an example, according to a 2006 book. There are in fact a number of options. In addition to sorting them under "Mac" and "Mc" respectively or choosing to sort them both under "Mc", it is known for Mc/Mac names to be placed in position before M. This topic has a complicated and disparate history, spread over different continents and relating to different areas of indexing, cataloguing and filing. The idea of a collating sequence itself has evolved, over time, and the "Mac and Mc" together