Words that appear frequently within a document are important. Italicized words are important. Words in bulleted lists are important. Uppercase words are important. All other words are not particularly important.
Footnotes are unimportant.
Conjunctions, prepositions, articles, and auxiliary verbs are particularly unimportant. The algorithm assigns auxiliary values to the records by preemptively applying assumptions such as these. Then, when the search algorithm reads the database, these values are used to help rate the hits. Articles written in Spanish can be emphasized for Latin American audiences. Online documents with images can be devalued to discourage long downloads.