I am using samsung mobile so i get the list.
*#9125# : Smiley
*#9999# : Software Version
*#06# : IMEI Number
*#0001# : Serial Number
*#9998*523# : LCD Contrast
*#0228# or *#8999*228# : Battery Info
*#8999*636# : Display Storage Capacity
*#8999*778# : Display SIM Card Information
*#8999*782# : Show Date And Alarm Clock
*#8999*786# : The Display During Warning
*#8999*837# : Samsung Hardware Version
*#0523# – *#8999*523# : Display Contrast
*#8999*638# : Show Network Information
*#9998*246# : Battery Status- Memory Capacity
*#9998*324# – *#8999*324# : Debug Screen
*#9998*842# – *#8999*842# : Vibration Test
*#9998*289# – *#8999*289# : Alarm Beeper – Ringtone Test
*#8999*9266# : Display Received Channel Number And Received Intensity
*#8999*364# : Watchdog ON/OFF
*#8999*427# : WATCHDOG Signal Route Setup
*2767*3855# : Full Reset (Caution every stored data will be deleted.)
*2767*2878# : Custom Reset
*2767*927# : Wap Reset
*2767*226372# : Camera Reset (deletes photos)
*2767*688# : Reset Mobile TV
#7263867# : RAM Dump (On or Off)
#*4773# : Incremental Redundancy
#*7785# : Reset wake-up & RTK Timer Variables
#*7200# : Tone Generator Mute
#*3888# : BLUETOOTH Test Mode
#*7828# : Task Screen
#*2562# : Restarts Phone
#*2565# : No Blocking? General Defense.
#*3353# : General Defense, Code Erased.
#*3837# : Phone Hangs on White screen.
#*3849# : Restarts Phone
#*7337# : Restarts Phone (Resets Wap Settings)
#*2886# : Auto Answer ON/OFF
#*7288# : GPRS Detached/Attached
#*7287# : GPRS Attached
#*2077# : GPRS Switch
#*22671# : AMR REC START
#*22673# : Pause REC
#*22674# : Resume REC
#*22675# : AMR Playback
#*22676# : AMR Stop Play
#*22677# : Pause Play
#*22678# : Resume Play
#*77261# : PCM Rec Req
#*77262# : Stop PCM Rec
#*77263# : PCM Playback
#*77264# : PCM Stop Play
#*22679# : AMR Get Time
#*7666# : White Screen
#*7693# : Sleep Deactivate/Activate
#*2286# : Data Battery
#*2679# : Copycat Feature Active/Deactivate
#*3940# : External Loop-Test 9600 bps
#*4263# : Hands Free Mode Activate/Deactivate
#*2558# : Time ON
#*3941# : External Loop-Test 115200 bps
#*5176# : L1 Sleep
#*7462# : SIM Phase
#*7983# : Voltage/Freq
#*7986# : Voltage
#*8466# : Old Time
#*2255# : Call Failed
#*5376# : Delete All Sms!!!!
#*2337# : Permanent Registration Beep
#*2474# : Charging Duration
#*2834# : Audio Path (Hands-free)
#*3270# : DCS Support Activate/Deactivate
#*3282# : Data Activate/Deactivate
#*3476# : EGSM Activate/Deactivate
#*3676# : Format Flash Volume!!!
#*4760# : GSM Activate/Deactivate
#*4864# : White Screen
#*7326# : Accessory
#*7683# : Sleep Variable
#*3797# : Blinks 3D030300 In RED
#*7372# : Resetting The Time To DPB Variables
*#8999*667# : Debug Mode
*#92782# : Phone Model (Wap)
#*5737425# : JAVA Mode
*#2255# : Call List
*#232337# : Bluetooth MAC Address
*#5282837# : Java Version
*#8999*8376263# : All Versions Together
*#8999*8378# : Test Menu
*#4777*8665# : GPSR Tool
*#8999*523# : LCD Brightness
*#8999*377# : Error LOG Menu
*#8999*327# : EEP Menu
*7465625*228# : Active Lock ON
#7465625*228# : Active Lock OFF
*7465625*28638# : Auto Network Lock ON
#7465625*28638# : Auto Network Lock OFF
*7465625*28782# : Auto Subset Lock ON
#7465625*28782# : Auto Subset Lock OFF
*7465625*2877# : Auto SP Lock ON
#7465625*2877# : Auto SP Lock OFF
*7465625*2827# : Auto CP Lock ON
#7465625*2827# : Auto CP Lock OFF
*7465625*28746# : Auto SIM Lock ON
#7465625*28746# : Auto SIM Lock OFF
*#7465625# : Check the phone lock status
*7465625*638*Code# : Enables Network lock
#7465625*638*Code# : Disables Network lock
*7465625*782*Code# : Enables Subset lock
#7465625*782*Code# : Disables Subset lock
*7465625*77*Code# : Enables SP lock
#7465625*77*Code# : Disables SP lock
*7465625*27*Code# : Enables CP lock
#7465625*27*Code# : Disables CP lock
*7465625*746*Code# : Enables SIM lock
#7465625*746*Code# : Disables SIM lock
These codes can be used whenever in need to check the info or usability and also as the security codes or reset codes for your Samsung phones.
Hope this list had helped you !