40 CFR § 1036.135 - Labeling.
Label your engines as described in 40 CFR 86.007-35(a)(3), with the following additional information:
(c) Identify any limitations on your certification. For example, if you certify heavy heavy-duty engines to the CO2 standards using only transient cycle testing, include the statement “VOCATIONAL VEHICLES ONLY”.
(d) You may ask us to approve modified labeling requirements in this part 1036 if you show that it is necessary or appropriate. We will approve your request if your alternate label is consistent with the requirements of this part. We may also specify modified labeling requirement to be consistent with the intent of 40 CFR part 1037.
The following state regulations pages link to this page.