What identifiable information is there in NYSE stock trades?

The CTA’s Consolidated Tape System and Consolidated Quote System:

The CTA is one of two Security Information Processors (SIPs) for US equities. It disseminates trades and quotes from securities listed on the New York Stock Exchange (NYSE) as well as those listed on a number of other exchanges – NYSE Arca, NYSE American, NYSE Chicago, IEX, and Cboe’s BYX, BZX, EDGA and EDGX. The market data is distributed on two networks—Tape A and Tape B—NYSE’s listings on the former and the rest of the exchanges listed on the latter.

Acquisition and Distribution of Market Data:

CTS and CQS receive trade and quote information, respectively from NYSE, AMEX, and the other regional market centers using a standard message format. Each system validates its respective message format, verifies the information against its databases (e.g., valid symbol, etc.), consolidates the information with the other market centers' information, and disseminates the information to the data recipients in its respective common standard message format via the IP Multicast network. Included in every trade and quote message is a timestamp which represents the time that the message is disseminated.

Every trade and quote is stored in the system for both on-line and after hours processing. Each system maintains a master database by symbol. CTS maintains in its database, by symbol, a consolidated high, low, last price and volume; and for each market center that trades that symbol, the market’s last sale and volume information. This information is updated with each trade.