The CH388 undocumented or hidden features:

• Press *#06# to display IMEI.
• *#0000# to reset the phones menu-language to English.
• >*<<*<* for checking the firmware revision information
  

  CXC125043 - Cell phone's internal product code. PRG - Firmware revision - software version (date & 970827 1606 time stamp).

• >*<<*<*> 1-row text strings. After selecting “yes” you can check the phones text programming in currently selected language. (298 entries).
• >*<<*<*>> n-row text strings.  After selecting “yes” you can check the phones text programming in currently selected language. (160 entries).

CH388 rarities or design flaws

• None at the moment