Del. Code tit. 25 § 81-215
A declarant may maintain sales offices, management offices, and models in units or on common elements in the common interest community only if the declaration so provides and specifies the rights of a declarant with regard to the number, size, location, and relocation thereof. In a cooperative or condominium, any sales office, management office, or model not designated a unit by the declaration is a common element. If a declarant ceases to be a unit owner, the declarant ceases to have any rights with regard thereto unless it is removed promptly from the common interest community in accordance with a right to remove reserved in the declaration. Subject to any limitations in the declaration, a declarant may maintain signs on the common elements advertising the common interest community. This section is subject to the provisions of other state law and to local ordinances.
25 Del. C. § 81-215