D.C. Code § 48-803.04: Dispensation of equivalent products by pharmacists — Recording and labeling required.

When a drug is substituted under this subchapter, including the substitution of an interchangeable biological product, the pharmacist shall record on the prescription form the drug substituted by name and manufacturer, and retain the form for inspection by District officials. The pharmacist shall also label the prescription container with the name of the drug substituted, unless the prescribing physician writes “do not label,” or words of similar import, on the prescription, or, in communicating the prescription by telephone, orders that the container not be so labelled.