How to check conflicts while applying CPU patch?

Please use below command to check the conflicts aganist the oracle_home and avoid to land in problems

step 1: unzip your patch zip file
step 2: run below command
$ORACLE_HOME/OPatch/opatch prereq CheckConflictAgainstOHWithDetail -phBaseDir

Example:

$ unzip p9655017_10204_linux.zip
$ $ORACLE_HOME/OPatch/opatch prereq CheckConflictAgainstOHWithDetail -phBaseDir 9655017
The other day, when I am doing patching on a RAC database, after executing the above conflict command, got below error

Following patches have conflicts. Please contact Oracle Support and get the merged patch of the patches :
6600051, 8836683
Whenever you get this type of error message, plz contact oracle support by raising a service request(SR)

In my case, Oracle support suggested to apply a merge patch 9347333 before applying Jul CPU 2011. Once done with applying merge patch, without any further issues I successfully applied CPU patch

Sometimes apart from above message you may see below warning messages which you can ignore

Summary of Conflict Analysis:

Patches that can be applied now without any conflicts are :
10013975, 10014009, 10014012, 10014015, 10325878, 10325885, 11787762, 11787763, 11787765, 11787766, 12419249, 12566121, 12566124, 12566126, 12566129, 12566131, 12566134, 12566136, 12566137, 12566139, 12566141, 12566142, 12566143, 7155248, 7155249, 7155250, 7155251, 7155252, 7155253, 7155254, 7197583, 7375611, 7375613, 7375617, 7609057, 8309592, 8309632, 8568395, 8568397, 8568398, 8568402, 8568404, 8836667, 8836671, 8836675, 8836677, 8836678, 8836683, 8836684, 8836686, 9173244, 9173253, 9442328, 9442331, 9442339, 9678690, 9678695, 9678697

Following patches are not required, as they are subset of the patches in Oracle Home or subset of the patches in the given list :
10249540, 8836681, 8568405

Following patches will be rolled back from Oracle Home on application of the patches in the given list :
10013975, 10014009, 10014012, 10014015, 10325878, 10249540, 8836681, 8568405, 7155248, 7155249, 7155250, 7155251, 7155252, 7197583, 7375611, 7375613, 7375617, 7609057, 8309592, 8309632, 8568395, 8568397, 8568398, 8568402, 8568404, 8836667, 8836671, 8836675, 8836677, 8836678, 8836683, 8836684, 8836686, 9173244, 9173253, 9442328, 9442331, 9442339, 9678690, 9678695