gistfile1.txt

http://wiki.typo3.org/Pagetree#Context_menu

    options.contextMenu {
        table.pages.items {
            710 = ITEM
            710 {
                name = notInMenu
                label = Hide in menu
                icon = ' . t3lib_div::locationHeaderUrl(t3lib_extMgm::extRelPath($_EXTKEY) . 'ext_icon.gif') . '
                spriteIcon =
                displayCondition = getRecord|nav_hide = 0
                callbackAction = tcemain-callback
                customAttributes = [some syntax where you set nav_hide]
            }
        }
     }