IME_FLAG_FORCE_ASCII
Flag of imeOptions: used to request an IME that is capable of inputting ASCII characters.
The intention of this flag is to ensure that the user can type Roman alphabet characters in a android.widget.TextView. It is typically used for an account ID or password input.
In many cases, IMEs are already able to input ASCII even without being told so (such IMEs already respect this flag in a sense), but there are cases when this is not the default. For instance, users of languages using a different script like Arabic, Greek, Hebrew or Russian typically have a keyboard that can't input ASCII characters by default.
Applications need to be aware that the flag is not a guarantee, and some IMEs may not respect it. However, it is strongly recommended for IME authors to respect this flag especially when their IME could end up with a state where only languages using non-ASCII are enabled.