How to flash Samsung Stock/Official ROM via Odin

Your Samsung device may experience following "symptoms":Device status will become "Custom/Modified", instead of "Official";Go to Settings > About device > Status > Device Status > CustomBoot into download mode and find out system status is CustomCannot receive OTA update.And you may wonder...How to restore phone status from "Custom/Modified" to "Official"?How to receive OTA update after rooting?