Article 280c 1.

there shall be one credit reference entity for each issuer of a reference debt instrument that underlies a single-name transaction allocated to the credit risk category; single-name transactions shall be assigned to the same credit reference entity only where the underlying reference debt instrument of those transactions is issued by the same issuer;

there shall be one credit reference entity for each group of reference debt instruments or single-name credit derivatives that underlie a multi-name transaction allocated to the credit risk category; multi-names transactions shall be assigned to the same credit reference entity only where the group of underlying reference debt instruments or single-name credit derivatives of those transactions have the same constituents.