Iron(II) hydroxide
Iron(II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH). It is produced when iron(II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidized solid is sometimes known as "green rust".
Ticker symbol
Symbols sometimes change to reflect mergers. Prior to the 1999 merger with Mobil Oil, Exxon used a phonetic spelling of the company "XON" as its ticker symbol. The symbol of the firm after the merger was "XOM". After Hewlett-Packard merged with Compaq, the new firm took on the ticker symbol "HPQ". (The former symbols were HWP and CPQ.) AT&T's ticker symbol is simply "T"; accordingly, the company is referred to simply as "Telephone" on Wall Street (the T symbol is so well known that when the company was purchased by SBC, it took the AT&T name, capitalizing on its history and keeping the desired single letter symbol).