Pressing on the Persian keyboard will toggle the mouse input between virtual QWERTY keyboard and virtual Persian keyboard. The key will also turn on/off your keyboard input conversion. Pressing on your keyboard has the same function.
The zero-width joiner (Z-W-J) can be used to make a character appear in its connected form by itself. It is invisible and located on the [`] key (typing م followed by the Z-W-J yields م).
The zero-width non-joiner (Z-W-N-J) is used if two characters are not intended to be connected. It is invisible like the Z-W-J and it is located on [shift][b] key (typing م followed by the Z-W-N-J followed by م yields مم).