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Navigate to the Project Setup page. In the Enable optional modules and customizations section, click Additional Customizations.
Scroll down to the Missing Data Codes section. Enter both the codes and the labels you want to use into the text box. To quickly add standardized codes, click the Add next to the appropriate code in the List of standardized missing data codes box. You may also enter custom codes manually. For more information regarding missing data codes, click Read more details instructions.
To utilize missing data codes when entering data in a record, click the M button next to the field and then choose from the list of missing codes. To remove a missing data code, click the M button and select Clear Value.
