1202.02(c)(ii) Descriptions of Trade Dress Marks Required
An application for a trade dress mark must include an accurate description of the mark. See 37 C.F.R. §2.37. If an acceptable statement describing the mark is not in the record, the examining attorney must require the applicant to submit a description to clarify what the applicant seeks to register. The description must adequately describe the mark, with unnecessary matter kept to a minimum. The description must clearly indicate that the mark is "three-dimensional" and constitutes "product design" or "configuration" of the goods themselves or product "packaging" or a "container" in which the goods are sold, or that the trade dress is for services offered (e.g., interior of a restaurant, exterior of a retail establishment, or point-of-sale-display such as a costume used in connection with the services).
If applicable, the description must specify which elements on the drawing constitute the mark and are claimed as part of the mark and which are not. The description of the mark must make clear what any broken or dotted lines represent and include a statement that the matter shown in broken or dotted lines is not claimed as part of the mark. See 37 C.F.R. §2.52(b)(4); TMEP §§808-808.03(f). This information must be included in the description. Statements only in a response to an Office action or elsewhere in the record are insufficient. The description must also avoid use of disclaimer-type language, such as "no claim is made to the …," because of the different legal significance of using broken lines versus submitting a disclaimer. See TMEP §1202.02(c)(iii) regarding disclaimers of unregistrable elements of trade dress marks.
In cases where the drawing depicts a two-dimensional mark that could be interpreted as three-dimensional in nature, an applicant may clarify that the mark is two-dimensional in the mark description. See TMEP §808.02. If the mark is two-dimensional in nature, the applicant should not characterize the mark as three-dimensional (e.g., that the mark " appears three-dimensional").
During the prosecution of a trade dress application, if the applicant is required to submit an amended drawing (e.g., showing broken or dotted lines to depict functional matter, to indicate nondistinctive and incapable matter, or to depict matter otherwise not claimed as part of the mark), the examining attorney must also require a corresponding amended description.
Examples of acceptable language for this purpose are: "The broken lines depicting [describe elements] indicate placement of the mark on the goods and are not part of the mark" or "The dotted lines outlining [the goods] are intended to show the position of the mark on the goods and are not part of the mark."
For example, for the mark below,

an appropriate description (and color claim) of the mark could read:
The colors white, blue, light blue, and silver are claimed as a feature of the mark. The mark consists of the color blue applied to the cap of the container of the goods, a white background applied to the rest of the container, a blue rectangle with a silver border, a light blue curving band, and three light blue droplets. The dotted lines outlining the container and its cap indicate placement of the mark on the goods and are not part of the mark.

an appropriate description (and color claim) of the mark would read:
The color red is claimed as a feature of the mark. The mark consists of a single transverse red stripe applied adjacent to one end of the three-dimensional elongated packaging for the goods. The dotted outline of the packaging is intended to show the position of the mark and is not part of the mark.

an appropriate description of the mark would read:
The mark consists of a three-dimensional configuration of a stringed musical instrument body. The neck, peghead, and other instrument parts shown in broken lines serve to show positioning of the mark and form no part of the mark.
The examining attorney must ensure that the description statement has been entered into the Trademark database, so that it will be printed in the Official Gazette and on the certificate of registration. See TMEP §817.
See TMEP §§1202.05(d)(i) and (d)(ii) regarding drawings in applications for color marks consisting solely of one or more colors.