Mnemonics should be shown on Windows in context menu when the context menu is requested by the keyboard

On Windows, the mnemonics on menu items are shown dependent on the properties of the os, or in cases where the Alt key is used or the keyboard focus is on the menu for some other reason.

This means that by default the mnemonics are not shown on context menus. However, when a context menu is requested using the context menu key on the keyboard, the context menu is useless when there are no mnemonics visible.

In case the keyboard context menu key is used, the mnemonics should always be shown. This is also the case for Internet Explorer and other MS products.