The appellees, Baynard Court, Inc., and Joseph W. Remedio, Inc., filed a mandamus action in Superior Court to compel the appellants, City of Wilmington and its appropriate officers, to issue a building permit to the appellees for construction of a medical office building on land zoned R-5-B. The Court below directed the issuance of the mandamus, whereupon this appeal was filed.

The facts are fully set forth in the opinion of the Court below, 273 A.2d 275. For the reasons set forth in that opinion, we affirm. If, as appellants argue, the inclusion in the Municipal Code of medical offices as a permissible use in the R-5-B classification was a mistake, the Courts cannot correct that error; it may be corrected only by the municipality itself. The appellees were entitled to rely upon the Code provisions as they appeared upon the books at the time of the application. Monacelli v. Grimes, Del.Supr., 99 A.2d 255 (1953).

Affirmed.