RLD

RLD is an acronym that can refer to multiple terms depending on the context. It is used in pharmacology and regulatory affairs as well as in urban geography, and may also serve as an internal shorthand in various organizations. Because of its multiple meanings, the appropriate interpretation is usually determined by the subject area being discussed.

Reference Listed Drug: In regulatory science, RLD stands for Reference Listed Drug. It denotes the standard drug product identified by the U.S. Food and Drug Administration as the comparator for a generic version in an abbreviated new drug application (ANDA). The RLD helps define the active ingredient, dosage form, strength, route of administration, and labeling used to assess bioequivalence. The FDA’s Orange Book lists RLDs and related patent and exclusivity information. If a brand-name product changes its formulation, the RLD may be updated, and generics must demonstrate sameness to the current RLD.

Red Light District: In urban and cultural contexts, RLD is sometimes shorthand for a Red Light District, a neighborhood where sex work is concentrated and visible. The term is most closely associated with Amsterdam’s De Wallen but has been used for similar districts in other cities. The origin of the phrase stems from historical lighting practices, though the existence, regulation, and legality of such districts vary by location.

Other uses: Beyond these, RLD can stand for organization- or industry-specific terms, including internal project names or abbreviations. As with many acronyms, the meaning of RLD is best inferred from the surrounding topic and regional usage.