Apply the code "dcrmb" to records for resources cataloged according to the core-level guidelines found in Appendix C.  The fact that such records follow the core-level provisions of DCRM(B) is indicated by the value 4 assigned in the Encoding level (Leader/17) and the code "dcrmb" in 040 subfield $e.

See also:

Appendix A:  MARC 21 Descriptive Conventions Code