Right. But, whatever you cited, seems incomplete. Thats all.
For instance, is the definition at the link below, created in a law somewhere?
Title 26 is the law. I just gave it to you. You can't cite a website in a tax matter, even if the website is that of the IRS.
It also depends on the section of the law you're looking at. For example, the website you're referencing has to do with non-profits.