The STOP function cannot be changed but in certain circumstances the content of the message that is sent in response to a STOP request can be changed.
- The STOP function is a carrier-regulated command word that cannot be modified. Note that "QUIT" and "CANCEL" also function the same way for short codes.
- The STOP function cannot be controlled or modified by keyword.
- When multiple keywords are active for a number the mobile user will always receive the option to select which keyword they want to opt out of if they send "STOP."
- If the user is opted into only one keyword and sends STOP they will be opted out of all messages on that keyword.
- If the user is opted into multiple keywords and sends "STOP ALL" they will always be opted out of all keywords on that short code.
- Senders using a shared short code cannot change the content of the reply message that is sent in response to the user. Senders who maintain their own dedicated short code or text-enabled toll-free number (TFN) can change the content of the message that is sent in reply to a STOP but cannot change the function.