Only finds the search term if it appears at the beginning of a word. For example, &quot; \ < book &quot; finds &quot; bookmark &quot; , but not &quot; chequebook &quot; .
仅查找位于词首的查找条目。例如， &quot; \ < book &quot; 可查找到 &quot; bookmark &quot; ，而不会查找到 &quot; checkbook &quot; 。