For the SIP feeds, there is the CTA and the UTP plan and they cover Tapes A,B and Tape C respectively. Is there an easy way to check on google what tape a stock would belong to? Particularly when it comes to disambiguating A and B?
You can pull a list of all stocks easily. See this question. You can get
otherlisted.txt from here.
nasdaqlisted.txt is clearly Tape C.
otherlisted.txt contains an
Exchange column which can be used to determine Tape A or B. If it is
N it's listed at NYSE and therefore Tape A, otherwise it's Tape B.
Also, NYSE publishes a symbol list these days as well. FTP to
ftp.nyxdata.com and look at the
Tape A is NYSE-listed stocks. Tape C is NASDAQ-listed stocks. Tape B is the regionals, ie. everything else. Most of Tape B is on ARCA now days, though some of it is still on the NYSE MKT, formerly known as AMEX.
If you want to use Google Finance, just note that they prepend every symbol with the exchange its on. For example, if I search for "AAPL", Google will change this to "NASDAQ:AAPL" automatically, which means its on Tape C. Likewise, "SPY" becomes "NYSEARCA:SPY" (Tape B) and "BAC" becomes "NYSE:BAC" (Tape A).
A fun fact: most of ARCA's products are exchange-traded funds (ETFs), and most ETFs are listed on ARCA. So ETFs and Tape B have become synonymous. (A glaring exception is that QQQ is listed on NASDAQ.)
Also, up until a few years ago, all NYSE-listed symbols had three or fewer letters, while all NASDAQ-listed symbols had exactly four characters. This has changed recently and now all exchanges allow any symbology (to poach competitors' listings), but the trend is still pretty common.
FINRA also has a list of symbols with their related exchanges. It's updated twice a day and includes OTC symbols.