CRD V is the fifth package of the
Capital Requirements Directives (
CRD) for the financial services industry. The Directives were introduced by the EU to reflect the Basel II and Basel III rules on capital measurement and capital standards (such as liquidity requirements as you mentioned) for banks and other financial services which were introduced following the 2007/2008 Global Financial Crisis.
The Bank of England has produced a note explaining the changes which I'll link below:
Consultation Paper 12/20
www.bankofengland.co.uk