How to Turn On “About This Page” in Oracle R12 OAF Pages

Set Following Profile Options as Required at User or Site (System Administrator -> profile)
Personalize Self-Service Defn = YES
FND: Personalization Region Link Enabled = YES
Disable Self-Service Personal = NO (Only at Site)
FND: Diagnostics = Yes
Bounce the Apache Server (not needed if you can wait for 30 minutes)
Login to Application you can see the About This Page Link on all web pages
By Using About This Page link you can see queries used by various regions, LOVs etc.