17. The system of claim 14 , wherein the processing system is further configured to: identify one or more tags in the electronic resource; parse content text associated with each of the identified tags to determine whether the content text matches a normalized data entry; and mark an identified tag of the electronic resource with a navigation filter heading annotation in response to a determination that the content text associated with the identified tag matches one or more of the normalized data entries.
19. The system of claim 17 , wherein the processing system is configured to, for each of the identified tags: determine whether the tag is a child node of a hyperlink; and remove the tag from consideration as a potential navigation filter heading in response to a determination that the tag is a child node of a hyperlink.