D.C. Mun. Regs. tit. 27, r. 27-2501
Items to be procured shall be described by citing the applicable specifications and standards or by a description containing the necessary requirements.
The using agency shall review and select from available specifications, standards, and related documents those specifications and standards which have application to a particular procurement. The specification or standard shall be modified or tailored to state the District's minimum requirement.
When authorized in accordance with this chapter, or when no applicable specification exists, the using agency may use a purchase description.
Each purchase description shall set forth the essential physical and functional characteristics of the materials or services required.
Each purchase description shall include the following characteristics, when applicable:
A purchase description shall not be written to specify a product, or a particular feature of a product, that is peculiar to a single manufacturer (thereby precluding consideration of a product manufactured by another company) unless the particular feature is essential to the District's requirements, and that other sources' similar products lacking that particular feature would not meet the minimum requirements for the items.
Purchase descriptions of services shall outline the specific services the contractor is expected to perform to the greatest degree practicable.
When applicable, the using agency shall include in the purchase description requirements for adequate packaging and marking of goods to prevent deterioration and damage during shipping, handling, and storage.
The contracting officer shall ensure that the specifications and standards included in the solicitation are not unduly restrictive and promote competition to the maximum extent possible.
D.C. Mun. Regs. tit. 27, r. 27-2501