Yealink SIP-T54S Administrator's Manual page 305

The following shows a portion of the keypad input method file "Russian_ime.txt":
To customize a keypad input method file:
Open the desired keypad input method file (e.g., ime.txt) using an ASCII editor.
1.
Under the input method field (e.g., [abc]), add new characters or adjust the characters
2.
order within the double quotation marks on the right of the equal sign.
Don't modify the item on the left of the equal sign.
Configuring Basic Features
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