http://pastebin.com/eRSUiTpr The rules.
It isnt quite natural route, since you can skip things like lens of truth. You can skip slingshot and hoverboots as well.
You can do some skips that require no glitching, like the precise jump b1 skip in deku, or rolling to the door in jabu from the switch.
Theres also lots and lots and lots of smaller timesavers everywhere that are allowed.
The issue with rule definition is that not everyone will agree on what is a glitch. A perfect example of this is using bombs to damage Volvagia while she is flying around, which is allowed, but many people consider it to be a glitch. Its important to note that these rules are set by a mostly japanese community that actually call the category "glitch restricted" and not "glitchless"