The U.S. crisis in subprime home mortgages has been and still is in the news, for example:
There has also been news about the impact of the subprime mortgage crisis on many parts of the economy, e.g., on banks:
Comprehensive works on (and the economics of) subprime home mortgages are classed in 332.722 Home finance (Residential finance), e.g., Subprime Mortgages: America's Latest Boom and Bust. Since subprime mortgages do not approximate the whole of the number, no standard subdivision is added.
Comprehensive works on many kinds of home mortgages in the United States are classed in 332.7220973 Home finance in the United States (built with 332.722 plus notation T1—09 Geographic treatment plus T2—73 United States), e.g., The Mortgage Answer Book: Choosing the Right Loan for You. Mortgages are treated as approximating the whole of real estate finance, as notes under 332.72 Real estate finance and mortgages make clear:
Standard subdivisions are added for either or both topics in heading
Class here discrimination in mortgage loans; mortgage delinquencies and defaults
Works on mortgage lending from the viewpoint of banks offering loan services are classed in 332.1753 Loans, e.g., Introduction to Mortgage Lending. Notes at 332.7 Credit make clear that credit functions of specific kinds of financial institutions are classed with the institution:
Class credit functions of banks in 332.1; class credit functions of specialized banking institutions in 332.2; class credit functions of credit and loan institutions in 332.3
Comprehensive works on (and the economics of) mortgage-backed securities are classed in 332.6323 Bonds ("Including mortgage bonds and certificates"), e.g., The Handbook of Mortgage-Backed Securities.
Works about the impact of the subprime mortgage crisis on specific parts of the economy are classed with the part, e.g., banks and banking 332.1 Banks.