Flitch Rating Structure can be summarized as under:

AAA
Highest Credit Quality: Exceptionally strong capacity for payment of financial commitments.

AA
Very high Credit Quality: Very strong capacity for payment of financial commitments.

A
High Credit Quality: Strong capacity for payment of financial commitments.

BBB
Good Credit Quality: Adequate capacity for payment of financial commitments, but depending on economic and financial conditions.

BB
Speculative. Though business or financial flexibility may exist that support servicing of financial commitments, vulnerable in the event of adverse changes in financial and economic conditions.

B
Highly Speculative.  Financial commitments are currently being met, but capacity for continued payment is vulnerable.

CCC
Substantial Credit Risk.

CC
Very high levels of Credit Risk.

C
Exceptionally high levels of Credit Risk.