Ammonia solution
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH(aq). Although the name ammonium hydroxide suggests an alkali with composition [NH][OH], it is actually impossible to isolate samples of NHOH. The ions NH and OH do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions.
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". Symbols are sometimes reused. In the US the single-letter symbols are particularly sought after as vanity symbols. For example, since Mar 2008 Visa Inc. has used the symbol V that had previously been used by Vivendi which had delisted and given up the symbol.