Arabic numerals (1–9 and 19 for business auto, 21–31 for garage, 41–50 and 59 for truckers, and 61–71 and 79 for motor carrier) used to denote to what category of autos a commercial auto policy's various coverages will apply. Symbols 10 (business auto), 32 (garage), 51 and 52 (truckers), and 72 and 73 (motor carrier) are custom symbols, available through the use of the covered autos designation symbol endorsement (CA 99 54), which allows the insurer and named insured to agree to some modified wording that is a better fit in defining the term "covered autos" for the policy in question.

Covered auto symbols, which are crucial in defining the policy's scope of coverage, appear in the declarations page of the auto policy next to each coverage purchased in the policy (e.g., liability, personal injury protection (PIP), auto medical payments, and uninsured and underinsured motorists (UM/UIM)). The symbols reflect the named insured's selection as to what types of vehicles are insured for that coverage (e.g., owned autos, hired autos, nonowned autos).