Concept
Markup might be as old as writing on media. The image below shows the annotation of a handwritten manuscript by Isaac Newton[3] (1643 - 1727 AD), where he discarded passages and made corrections to existing text. The next one is a combination of handwritten notes and highlighted passages made by a so-called marker[4], the device where the name markup language originates from. The picture on the right might already be considered a type of markup language, in which each colour represents a certain meaning (yellow=name, blue=date, etc) which is explained in the legend next to it. This ensures that other parties/machines can understand what is meant by the different colours/markup as well, which is exactly what a markup language is supposed to do.
