BDI represent Bi-Directional Isolation.
The bdi element represents a span of text that is to be isolated from its surroundings for the purposes of bidirectional text formatting.
This tag is useful when displaying a text when direction of text is unknown.
For example, arabic text will be from right-to-left, by using this tag arabic text can be written in left-to-right direction.
The following example doen't work properly.