W is a new code that means "Bypass Trade"
We will update the documentation shortly.

Regulatory Trade - indicating the "hidden" or iceberg portion of the order
was not satisfied. Depending on whether the trade was used to move the price
down in accordance with UMIR, or the ByPass Cross was put up, it may or may
not set the last sale price. Please use the K marker to determine the last
sale price.
They are also included in the volume, value, and number of transactions.

http://www.tmx.com/en/trading/rules_regulations/umir.html

http://www.tmx.com/en/pdf/notices/2009-024.pdf