Button URL specific record with Everyone on the Internet

That is something is was trying to figure out as well.  How if I have a field with a "secret" code within record can I send it in on the URL to bring up that specific record.  More importantly, how could I then limit that EOTI Role to only that record based on that "secret" code.  I think we are both going down the same thought path, I just may lack the experience in the URL with an extra field.