Every stock traded on the world's stock exchanges is identified by a short symbol.
T. These symbols date from the days when stock trades were reported on a ticker tape. Ticker symbols are still used today as brief, unambiguous identifiers for stocks. Similar abbreviations are used for stock options and many other securities. Ticker symbols get reused on different exchanges, so you'll sometimes see a qualification ahead of the ticker symbol. The stock quote services on the web usually understand this notation.