What must be used to find a one-word exact phrase in Keyword Search?

Using quotation marks is necessary to find a one-word exact phrase in Keyword Search because they tell the search engine to treat the words within the quotes as a single unit. This means that the search will specifically look for instances where those exact words appear together in that order, rather than separately or in varied contexts. Quotation marks help to refine the search results, making it easier to locate precise phrases or terms that should be taken literally rather than being interpreted loosely.

Other methods such as parentheses are typically used for grouping search terms or combining different search queries, wildcards allow for variations of a term, and brackets are sometimes employed for different types of searches, but none of these methods provide the specificity in searching for exact phrases that quotation marks do.