15. The system of claim 14 , wherein prior to conditionally confirming the authorship of the first document by the entity associated with the second document, the at least one program includes instructions to: identify a first link in the first document that links to the second document, wherein the first link includes the first predefined authorship attribute; access the second document; and determine that the second document includes the second link including the second predefined authorship attribute.
14. A system to confirm authorship of documents, comprising: at least one processor; memory; and at least one program stored in the memory and executable by the at least one processor, the at least one program comprising instructions to: access a first document hosted on a first website of a first domain, the first document being indirectly linked to a second document through at least one link in a chain of links, a respective link in the chain of links including a first predefined authorship attribute asserting authorship of a respective document including the respective link by a respective entity associated with a respective target document of the respective link; and conditionally confirm authorship of the first document by an entity associated with the second document when the second document includes a second link to the first website of the first domain, the second link including a second predefined authorship attribute indicating that the entity associated with the second document is an author of or contributor to content at the first website of the first domain.