This validation checks if a menu string contains hotkey that is also used by some other string in the same menu. Hotkey is special character that marks another character that specifies what character actives that item. Ampersand (&) is used as hotkey mark character on most platforms (Visual C++, VCL and .NET). WPF uses underscore (_). Duplicate hotkey prevents using the hotkey on second item and on some platforms it might disable hotkeys on all items. Change all hotkeys but the first one to remove duplicates. Sisulizer suggest you the available hotkey characters that do not conflict. If you validating translations Sisulizer can automatically fix duplicate hotkey if you click Fix button.For example if you have two menu items : "&Save" and "Check and &save" on your menu you have duplicate S hotkey.
This validation can be applied both to original and translated strings.