| dark websearch | Noun phrase. Web search conducted outside or beyond the brand search services such as Baidu, Bing, Google, Yahoo!, and Yandex. Site search is one form of Dark Websearch; online database search is another form of Dark Websearch. May also be called Closed Websearch. |
| term naturality | Noun phrase. The sum of the measured natural value of all Natural members in a group, as used in the Theorem of Search Engine Optimization formula. Cf. Naturality. |
| safe search | Web Search that does a better job of filtering inappropriate content |
| opt-in | Marketing initiatives in which a user chooses to participate. For example, an opt-in newsletter requires the user to input an email address in order to opt-in and receive the newsletter. |
| indexed page | A webpage that has been discovered by a crawler, has been added to a search engine index, and is eligible to appear in search results for relevant queries. |
