| advanced search operators | Special characters and commands you can type into the search bar to further specify your query. |
| micro opacity | Noun phrase. The measurement of site-level opacity (q.v.). |
| domain name registrar | A company that manages the reservation of internet domain names. Example: GoDaddy. |
| doorway | Noun. A document with a small amount of text (usually coherent but sometimes gibberish) intended to rank well specifically for one targeted expression. In the old days, people created as many doorways as they had targeted keywords and search engines to work with. |
| referring domains | otherwise known as a ref domain, a referring domain is a domain that a backlink is coming from. |
