Block: Box Drawing

Range U+2500 - U+257F
Official Chart http://www.unicode.org/charts/PDF/U2500.pdf
Wikipedia Box-drawing characters, also known as line-drawing characters, are a form of semigraphics widely used in text user interfaces to draw various geometric frames and boxes. In graphical user interfaces, these characters are much less useful as it is more simple and appropriate to draw lines and rectangles directly with graphical APIs. Box-drawing characters work only with monospaced fonts; however, they are still useful for plaintext comments on websites.
https://en.wikipedia.org/wiki/Box_Drawing
Characters