Key:

• Rule numbering and titles taken from DCRM(B) first printing 
• Module code in parentheses before rule number indicates location of original text to be changed; module code after description of needed change indicates that the change has been made in that module; module code after plus "n/a" means change has been verified as not applicable to that module
• Because subsequent printings are based on an entirely new text supplied by BSC but Cataloger's Desktop is updated manually, there is occasionally a discrepancy between print and online that is to be noted and CD to be given the correction
• Additions to text are shown underlined; deletions are shown struck through
• Codes:
• {B, B1}, B2, B3, B4 = Books, first through fourth printings; "not done" indicates that the intended change was inadvertently not made
• C = Cartographic
• G = Graphics
• M = Music
• MSS = Manuscripts
• S = Serials
• CD = Cataloger's Desktop

MARC 21 Descriptive conventions code 

A4. Core-level DCRM(B)

1. (B) Delete entire rule; renumber subsequent rules and update references to renumbered rules (noted under relevant rule number(s) on wiki) (B4) 

A6A5. Microforms and digital reproductions of books

1. (B) "Apply the code 'dcrmb' to records ... (full, core, or minimal level). If however, DCRM(B) (full, core, or minimal level) ..." (B4)

A8A7. "Special collections cataloging"

1. (B) Final sentence: "Do not apply the code 'dcrmb' ... of DCRM(B) completely (full, core, or minimal level)." (B4)

A9A8. Earlier codes 

1. (B)(S) 040 $e no longer goes at end of field: "... delete the earlier code and add the “dcrmb” code to the end of the 040 field in subfield ‡e." (C)(G)(MSS)(B4)