When looking through Bloomberg's BSYM data ADR and Common Stock data (5/2/13), I was able to find the ticker symbol 'V' associated with Visa but was unable to find any record for Vivendi, which I believe also used 'V' at some point in time.
If BSYM is a truly unique identifier (which interests me since it's an open-source way to have a unique security ID), shouldn't I see at least one record for the Vivendi Universal ADR that also had the 'V' symbol?
Here's a more clear example: Chrysler used to trade under "DCX" (after they were bought by Daimler) ... that ticker appears nowhere in the Bloomberg BSYM data. So I'm assuming that a current view of the BSYM equity/common-stock list has survivorship issues (i.e. it's a great source of all current tickers but won't include any companies that no longer exist).