The Free On-line Dictionary of Computing (19 January 2023):

Control and Status Register
CSR

    (CSR) A special register in most CPUs that
   stores additional information about the results of machine
   instructions, e.g. comparisons.  The CSR consists of
   several independent flag bits such as carry, overflow
   and zero.  The CSR is chiefly used to determine the outcome of
   conditional branch instructions or other forms of
   conditional execution.

   (2018-01-29)