1. A form of calligraphy (beautiful hand writing), in medieval manuscripts, in which any added text was done with a red color: "When Samuel looked at the ancient manuscript, he noticed the first letter on each page was done as a rubrication."
2. Anything done in red; such as, a letter, a word, or some other part of a text that is presented separately: "Most computers spell check mispelled words as rubrications so they are easy to see."