Qualified Institutional Buyer - QIB

What Does Qualified Institutional Buyer - QIB Mean?
Primarily referring to institutions that manage at least $100 million in securities including banks, savings and loans institutions, insurance companies, investment companies, employee benefit plans, or an entity owned entirely by qualified investors. Also included are registered broker-dealers owning and investing, on a discretionary basis, $10 million in securities of non-affiliates.

Investopedia explains Qualified Institutional Buyer - QIB
QIBs are eligible to participate in the Rule 144A market.