Canadian Tax on Poker???

[Rebel88]

I was looking through the act respecting income tax for Canada and came across this:

Income not taxed

It is interesting to note what is not taxed in Canada. The following list is not comprehensive:
• gifts and inheritances;
• lottery winnings;
• winnings from betting or gambling for simple recreation or enjoyment;

My question is, to anyone with knowledge on the subject, what differentiates a gambler of simple recreation or enjoyment to a "pro"? Is it a monetary amount, if so what is the limit? If poker is you're sole means of income in Canada do you have to pay tax on it according to the law. I could not find anything in the act regarding gambling tax other than that of recreational play.