; and (2) amounts deposited with certain central banks , as determined through rulemaking by the appropriate Federal banking agencies. (d) Definitions For purposes of this section: (1) Appropriate federal banking agency The term appropriate Federal banking agency has the meaning given that term under section 3 of the Federal Deposit Insurance Act ( 12 U.S.C. 1813 ). (2) Custodial bank (A) In general The term custodial bank means a depository institution and the depository institution holding company of such depository institution, both of which are primarily engaged in custodial banking. (B) Custodial banking defined For purposes of this paragraph, the appropriate Federal banking agencies may define the term custodial banking based on factors including the percentage of total revenues generated by custodial businesses and the level of assets under custody. (3) Depository institution The term depository institution has the meaning given that term under section 3 of the Federal Deposit Insurance Act ( 12 U.S.C. 1813 ). (4) Depository institution holding company The term depository institution holding company has the meaning given that term under section 3 of the Federal Deposit Insurance Act ( 12 U.S.C. 1813 ). (5) Supplementary leverage ratio The term supplementary leverage ratio means the supplementary leverage ratio, including applicable buffers, surcharges, and well-capitalized requirements relating to such supplementary leverage ratio, as defined by regulation of the appropriate Federal banking agency in title 12, Code of Federal Regulations.