ValueClass
sealed trait ValueClass
Represented a context in which a finite set of types are valid.
Example:
<br-width> = <length> | thin | medium | thick
class Object
trait Matchable
class Any
trait Integer
trait Number
trait Time
trait Len
trait Pct
trait LenPct
trait LenPctAuto
trait LenPctNum
trait BrWidth
trait BrStyle
trait Color
trait WidStyCol
trait RepeatStyle
trait OverflowBehaviour
trait GapStyle