The term "sep 11 attack wiki" functions as a compound noun phrase. The main point, or head noun, is "wiki," which identifies the type of resource being referenced. The preceding words, "sep 11 attack," act as a noun adjunct, modifying the head noun by specifying the subject matter of the wiki. Therefore, the phrase identifies a specific entity: a collaborative online encyclopedia about the September 11 attacks.
In this grammatical construction, "sep 11 attack" is a proper noun phrase naming the historical events of September 11, 2001. When used as a noun adjunct, it loses its primary noun function to describe the subsequent noun, "wiki." This structure is highly efficient for information retrieval, as it narrows a broad category (wikis) to a precise topic. The phrase is not a sentence or clause; it is a single, identifiable concept treated grammatically as a noun.
The practical application of this analysis is in understanding user intent for search engines and databases. The phrase signals a clear request for a specific type of document (a wiki) about a specific subject (the September 11 attacks). This linguistic structure allows information systems to parse the query and deliver the most relevant result, which is typically the Wikipedia article titled "September 11 attacks." The entire phrase serves as a precise identifier for a piece of digital information.
