Did you know that you can set a preference to warn users if they try to record a transaction to the Retained Earnings account?
Click Edit > Preferences and select the Accounting preference on the left. Click the Company Preference tab (if you are logged in as the Admin or External Accountant user) and place a check mark in the Warn When Posting a Transaction to Retained Earnings check box. Users then receive the message shown below.
Click to enlarge:
From Laura Madeira’s QuickBooks 2010 Solutions Guide