These are CU-defined codes you can attach at both the membership level, as well as at the individual sub-account level, to indicate the reason why a member joined your credit union, and why they opened certain types of accounts.  In addition, you can also configure codes that explain why a member closes a sub-account, or why they leave the credit union entirely.  Both are valuable tools for your marketing and member service efforts as you work to respond to why members choose and use your products.
The membership-level flag is stored in a field called New Account Code (NEWACT) in the MASTER database table.  For closed memberships, the code is stored in a field called New Account Code (NEWACT) in the MSHIST database table.
NOTE: Unlike the account-level codes described below, there is only one reason code field at the membership level.  When a membership is closed, whatever open code was entered on the MASTER record is replaced with whatever closed reason code you designate when closing the membership, in the same NEWACT field in the MSHIST table.  (If you do not enter a closed reason, then the original open reason code remains.)
The account-level flags are stored in fields called Open Reason Code (RSNCDEOPN) and Close Reason Code (RSNCDECLO) in the MEMBERx table that stores account data.  For example, MEMBER1 stores data for savings and IRA accounts, including the member’s base share (suffix -000) account.  If an account is closed, then both the original open code as well as the closed reason code will be stored in the ACHISTx history table.