27. A non-transitory computer readable storage medium storing at least one program configured for execution by at least one processor of a computer system, 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.
27. A non-transitory computer readable storage medium storing at least one program configured for execution by at least one processor of a computer system, 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. 32. The non-transitory computer readable storage medium of claim 27 , wherein the second document includes a profile of the entity.