24 C.F.R. § 1006.110
(2) Notice of reasons for determination of noncompliance. If HUD determines that the contents of the housing plan do not comply with the requirements of § 1006.101, or are not consistent with information and data available to HUD, or are prohibited by or inconsistent with any provision of the Act and this part or any other applicable law, HUD will specify in the notice under paragraph (b)(1) of this section: