distance between centres of lines；distance between centers of tracks；midway between tracks

distance offset distance

A unique function

Adjointly unique

Administration unique methods

advantageous and unique industry

bottom-unique

Boundary unique contin- uation

chromatic unique graph

chromatically non-unique graph

chromatically non-unique graphs

Chromatically unique

chromatically unique graph

chromatically unique graphs

F-cover with the unique mapping property

Forging of unique characters

global unique identifier

globally unique time based number

GUID Globally Unique IDentification number