Similar to MBS but backed by loans secured with commercial rather than residential property. Commercial property includes multi-family, retail, office, etc., They are not standardized so there are a lot of details associated with structure, credit enhancement, diversification, etc., that need to be understood when valuing these instruments.
COMMERCIAL MORTGAGE BACKED SECURITIES
Meaning of COMMERCIAL MORTGAGE BACKED SECURITIES in English
Campbell R. Harvey. Hypertextual finance English glossary. Английский словарь гипертекстовых финансов. 2012