Double-check ticker symbols, OR you might be sorry

I was checking up on OMI, an oil tanker company mentioned favorably in Barron's (subscription required) a few weeks ago. It has been on my watch list for quite a while. So I typed "OMI" into the quote search, only to get a leading distributor of medical and surgical supplies-- that's not right. Then I remember the company I was interested in goes by the ticker OMM-- now that's better.

It seems like symbol confusion happens to me about once a month. Harley Davidson (HDI) is changing its symbol to HOG (see Harley Davidson - HDI will be HOG - and living high!) This will add a little confusion for a while, but I bet there are millions of people that have looked up HDI, but who actually wanted Home Depot, ticker HD.

Another one I have remembered wrong in the past is Alcoa Aluminum which uses 'AA' for it's stock ticker symbol. This makes sense, but what comes to mind first is American Airlines, which uses 'AA' for their logo, website (AA.com), and in most promotional material, and is actually AMR. 'AA - American Airlines' is also used as a slang term for a pair of aces in the hole in hold-em poker. 'WM' is Washington Mutual, not Waste Management which is 'WMI', or Wal-Mart which is 'WMT'

I'm sure ticker confusion is a common enough occurrence and that most of the time investors find the correct stock ticker for the company in which they are interested. Still, with so many millions of trades daily and so many of them done on low cost on-line trading sites by people with limited experience, I wonder how often someone does not catch the mistake.

Anyone else have ticker confusion or trades that they wanted busted due to ticker error? It's always worth double-checking before confirming a trade.

Sheldon Liber is the CEO of a small private investment company and the vice president for Design and Research of an Architecture & Planning firm.