The dir property may be set to indicate a left-to-right or right-to-left parsing direction.
This is part of the localization support and represents the contents of the DIR="..." tag attribute.
If you assign a value to this property it is case-sensitive and must be either "ltr" or "rtl". Note that this is at variance with some documentation which says it is case-insensitive.
This property works in conjunction with the lang property to control the direction of text flow.