It seems that people are getting confused between what Copyright Law is and what the United States wants the Law to be.
Copyright Law is international under the Berne Convention. Every country that is a member of the Berne Convention is bound by the exact same Copyright Law...and that is almost every country.
It is all very complex but I can sum it up like this...
Copyright is AUTOMATIC - You make it, you own it.
That is it...That is Copyright summed up.
There is no such thing as Copyright registration - Yes, I am aware that the U.S has a Copyright Office and I understand that they charge a fee. Under the Berne Convention the U.S Copyright Office is may NOT be lawful.
The question of linking to web sites by posting URL's. No, that does not breach Copyright. Some things are not subject to Copyright for example, your name, your address etc. A URL is nothing more than an address and therefore not Copyright.
Giving credit does NOT give a right of use. Whether the material has a Copyright Notice or not is irrelevent...It makes no difference. If you did not make it, then you do not own it!
The ONLY time at Law you can use Copyright material is if you own it or you have "express written permission" to use it.
There are uses that are exempt of the Copyright Law. For example...
Reporting News.
Education.
Critical Review.
etc, etc.
In short, if you are not 100% sure that you are allowed to publish material, then chances are you are not.
As for posting recipes etc. I would suggest that you take the time to type it yourself. If photos are required, then cook the recipe and take the photo yourself. I would suggest, that the question of whether a recipe is Copyright or not would need to be asked on an individual basis at Law.
At the end of the day the simplest thing to do is what Admin asks...Don't breach other peoples Copyright.