The nature of grounds whereupon a trademark may be opposed can differ. National and territorial trademark laws stipulate point by point and at times thorough arrangements of justification for opposition.
While a differentiation among absolute and relative grounds for opposition is acknowledged at large scale, not all frameworks do essentially follow that categorization, and oppositions may likewise be raised on any ground provided by law. Absolute grounds as a rule refers to the innate characteristics of the sign to work as a mark, and relative grounds identify with conflicts with established third party rights.
The reference to prior trademark rights incorporates unregistered trademark rights where they exist.