Applicability. This cost information applies to grant assistance awarded on or after the effective date of this regulation. Project cost determinations under this subpart are not limited to the items listed in this appendix. Additional cost determinations based on applicable law and regulations must of course be made on a project-by-project basis. Those cost items not previously included in program requirements are not mandatory for decisions under grants awarded before the effective date. They are only to be used as guidance in those cases.