The Command key (⌘), also historically known as the Apple key, clover key, open-Apple key, pretzel key, propeller key, squiggly button, or meta key, is a modifier key present on Apple Keyboards. The Command key's purpose is to allow the user to enter keyboard shortcut commands to GUI applications. An "extended" Macintosh keyboard—the most common type—has two command keys, one on each side of the space bar; some compact keyboards have one only on the left. The “⌘” symbol (the “Looped square”) was chosen after Steve Jobs decided that the use of the Apple logo in the menu system (where the keyboard...

Methylchloroisothiazolinone (5-chloro-2-methyl-4-isothiazolin-3-one), also referred to as MCI, is a preservative with antibacterial and antifungal effects within the group of isothiazolinones. It is effective against gram-positive and gram-negative bacteria, yeast, and fungi. Methylchloroisothiazolinone is found in many water-based personal care products and cosmetics. Methylchloroisothiazolinone was first used in cosmetics in the 1970s. It is also used in glue production, detergents, paints, fuels, and other industrial processes. Methylchloroisothiazolinone is known by the registered tradename...