Monosubstituted benzene derivatives are named as other hydrocarbons using the following set of rules:

1. Benzene is the parent name; when a benzene ring is a substituent on another chain, it is referred to as a "phenyl" group.
   

2. Disubstituted benzenes are named using ortho-, para- and meta- to describe the substitution pattern (1,2 1,4 and 1,3 respectively) or simply by numbering the substituents.
   

3. Substituents are numbered to give the lowest possible number sequence at the first point of difference, assigning priorities alphabetically if there is a "tie".
   

There are also a large number of common (or "trivial") names for arenes which are in common usage and students should strive to recognize these by both systematic and common names.

Many of these are acceptable "parents" with regard to nomenclature. When one of these is used as the parent chain, the substituent is position #1, by definition.

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