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The phone screen or standby screen UID in different versions of s60:

The standby screen UID is different for different series 60 versions, and different for different Feature Packs too.

The UID of standby screen (the process is called Phone) on 2nd edition is: 0x100058b3

The UID of standby screen (the process is called Phone) on 3rd edition is: 0x100058b3

The UID of standby screen (the process is called Standby Mode) on 3rd edition and 3rd edition FP1 is: 0x101fd64c

The UID of standby screen (the process is called Standby Mode) on 3rd edition FP2 is: 0x102750F0

The UID of standby screen (the process is called Home screen) on 5th edition is: 0x102750F0

So now if anyone wants to use the UID of standby screen, then one needs to define these with appropriate macros and use them. May be something like this:

#ifdef __SERIES60_3X__
const TUid KUidStandBy = { 0x101fd64c }; // For 3rd Edition
const TUid KUidStandBy_FP2 = { 0x102750F0 }; // For 3rd edition Emulator, FP2 and 5th edition devices
#else // #ifdef __SERIES60_3X__
const TUid KUidStandBy = { 0x100058b3 }; // For 2nd Edition
#endif // #ifdef __SERIES60_3X__

and then use it...

UIDs of running applications can be found using Y-Task.