Having two ``++WHEN++`` in the same ``++SELECT++`` statement or branches in the same ``++IF++`` structure with the same implementation is at best duplicate code, and at worst a coding error. If the same logic is truly needed for both instances, they should be combined.
But this exception does not apply to ``++if++`` chains without ``++else++``-s, or to ``++select++``-s without ``++other++`` clauses when all branches have the same single line of code. In case of ``++if++`` chains with ``++else++``-s, or of ``++select++``-s with ``++other++`` clauses, rule S3923 raises a bug.