Spelling sub-menu

This sub-menu of the Edit menu, contains the following items:

• Check spelling. This causes any items not matching the host OS' spelling list to be underlined in red.
• Check spelling as you type. Clicking this causes "Check spelling" to permanently turned on. The item acts as an on/off toggle (default = off). When turned 'on' a tick is shown in the left margin of the menu. This is set (per file?) on this menu - there is no preference setting.
• Ignore word. Tells the OS spell checker to cease highlighting the word under the cursor.
• Learn word. Tells the OS spell checker to add the word under the cursor to its dictionary.