https://bugs.winehq.org/show_bug.cgi?id=56026
--- Comment #2 from Grigory Vasilyev h0tc0d3@gmail.com ---
What's the functionality of buttons mouse3-mouse6 (do you start counting from 0, with mouse0-mouse2 as left/middle/right?) on your system, e.g., with WineX11?
mouse1 - Left Button, mouse2 - Right button, mouse3 - Scroll click
= mouse4 Side buttons click
For example, my mouse has 2 side buttons. These buttons can be assigned in games to perform different actions. Yes they are also called xbutton1 and xbutton2. But there are mice that have even more side buttons. Such mice are used in role-playing games, and there the number of side buttons can be more than 12! Example: https://www.rtings.com/mouse/reviews/best/mmo
type 4 (EV_MSC), code 4 (MSC_SCAN), value 90005 type 1 (EV_KEY), code 276 (BTN_EXTRA), value 1 -------------- SYN_REPORT ------------ type 4 (EV_MSC), code 4 (MSC_SCAN), value 90005 type 1 (EV_KEY), code 276 (BTN_EXTRA), value 0
type 4 (EV_MSC), code 4 (MSC_SCAN), value 90004 type 1 (EV_KEY), code 275 (BTN_SIDE), value 1 -------------- SYN_REPORT ------------ type 4 (EV_MSC), code 4 (MSC_SCAN), value 90004 type 1 (EV_KEY), code 275 (BTN_SIDE), value 0