The system prepares PDF documents to be digitally populated or signed. The method may comprise converting a document into an image; detecting words on the document; searching the words for keywords; searching for an object on the document; determining an object field based on the keywords and the object; creating a tag with metadata about the object field; and associating the tag with the object field. The method may also comprise determining, by a processor, metadata about a document; creating, by the processor, a hash from the metadata; storing, by the processor, an association of the hash, the metadata and the document in a knowledge database; creating, by the processor, a new hash for a new document; comparing, by the processor, the hash with the new hash; and determining, by the processor, that the new document has similar characteristics as the document based on the comparing.