Incorrect rel canonical , impacts ?

[ibusmedia]

Incorrect use of canonical code.. and why have they used the strange code surrounding it. Hi there seo guys, I need some help.. a site I am working on has used the rel canonical tag incorrectly. they have used the code on the cannon page not on the duplicate pages.. there is also some other strange code with it. I will show and hide the url.. However I wanted to know if this would stop google bots crawling this page correctly as they dont seem to rank very well either.. here is the code:

[Dr-Pete]

Yeah, I'm unclear as well - could you provide a sample URL, even if it's not the real URL (just something similar)?

If the canonical tag is appearing on both the original and duplicate and points to the original, that's fine. Google will essentially just ignore it on the original. If the original points to the duplicate, though, or they both point to each other, etc., that could be very dangerous.

[donford]

The rel canonical code used incorrectly can very much hurt the site and page. Those should be fixed asap and sitemap re-submitted.

I'm not sure what you mean by strange code that shows / hides url, do you mean the tag with the url is dynamic? Can you post an example ?