Specification of Coordinates
- px
- Pixels (no units secified then pixels assumed)
- percentage (eg 60%)
- A fraction of the space allocated by the user agent
- pt
- Printing industry point (Postscript version: 1/72in)
- em
- Historically width of letter M, now font height (if font is 12pt then em=12pt)
- ex
- X-height, varies between fonts (12pt Times Roman 'ex' will be bigger than 12pt Baskerville 'ex')
- pc
- pica (1pc=12pt)
- cm
- Centimetres
- mm
- Millimetres
- in
- Inches
