14. The device according to claim 10 , further configured to: build a correspondence between the user-input tag and the structural information of the tagged document.
10. A device for tagging a document, the device comprising at least one processor, the device configured to: acquire a user-input tag; build a structural information repository and a tag document index repository by processing a predetermined document; acquire structural information of the document; retrieve a content block list corresponding to the user-input tag, wherein the content block list is stored in the tag document index repository; compare a content block in the structural information acquired with a content block in the content block list, thereby obtaining a similar block; and annotate the user-input tag at a position corresponding to the similar block in the document, thereby creating a tagged document.