Q:

What's the maximum mouse buttons a mouse can have?

hey there guys i need your help i'm making a game engine and i don't know what to put as the maximum amount of mouse buttons you can use. Meaning how many mouse buttons can have? 
Mouse button:
For example the right or left mouse button or the middle mouse button

A:

The USB HID standard (page 61) allocates bits for three buttons. But there is also a four-bit value that is device-specific. If treated as a four-bit number instead of four discrete flags, then you can have up to fifteen additional buttons.

