Md. Code, Real Property § 7-108

Any person may record among the land records of any county an unexecuted declaration of provisions, covenants, and conditions, and any mortgage or deed of trust thereafter recorded among the land records of the county where the declaration is recorded may incorporate any provision, covenant, or condition of the declaration into the mortgage or deed of trust by specific reference to it and to the liber and folio of the declaration, if the intention to incorporate by reference is shown clearly, and the mortgagor or grantor is furnished a copy of the declaration when the mortgage or deed of trust is executed.