middle_mouse_button_functions

1.In its style guide, Microsoft states that the middle button "should be assigned to operations or functions already in the interface," a definition it once reserved for the right mouse button.
在微软的风格指南中说，中间键“应该分配给界面上已有的操作或功能”而一度将它定义为右键的储备。
dict.yoduao.com