e-Documents are documents in electronic formats such as document files or image files, etc. The currently preferred e-document format is PDF due to its ability to preserve the document’s display. The PDF format is a format for preparing e-documents. Development began from PDF files stored as images such as paper document scans. Later, PDF files were developed to store data with the ability to increase-reduce boxes. This format was called “PDF/XFA”. However, this format continued to have limits in attaching other files. Therefore, the PDF format was developed into the current PDF/A format. PDF/A files can be stored long term because the values necessary for opening and using files are already stored in the file. In particular, PDF/A-3 files have properties allowing attachment of many types of files. When XML files are attached, the system can draw on XML files to continue processing while document users can read data from PDF files.
XML Schema Design