12 CFR §725.19

1. (a)Each Facility advance and each Agent loan shall be secured by a first priority security interest in collateral of the credit union with a net book value at least equal to an amount as required by the Facility's collateral table, published at www.NCUA.gov, or by guarantee of the National Credit Union Share Insurance Fund.
2. (b)The Facility may accept as collateral for each Facility advance to a Regular member or to an Agent member, for such Agent member's own needs, a security interest in all assets of the member; provided however, that the value of any assets in which any third party has a perfected security interest that is superior to the security interest of the Facility shall be excluded for purposes of complying with the requirements of paragraph (a) of this section.
3. (c)The Facility may accept as collateral for each Facility advance to an Agent member, a security interest in the Agent loans for which the Facility advance was made; provided however, that the collateral for such Agent loan meets the requirements of paragraph (a) of this section.