429. A bank must collect and store data on key borrower and facility characteristics to provide effective support to its internal
credit risk measurement and management process, to enable the bank to meet the other requirements in this document, and to
serve as a basis for supervisory reporting. These data should be sufficiently detailed to allow retrospective reallocation
of obligors and facilities to grades, for example if increasing sophistication of the internal rating system suggests that
finer segregation of portfolios can be achieved.