How can we archive document?

You can archive document by giving each document a unique file name with that you can always search for all your documents easily by just typing the document code you used in saving the file and everything you need to know about the file will appear, this is for electronic archive, then for manual archive, just make sure you give all your documents unique numbering also that will be easy for you  to trace any of the documents then put your documents in a shelf with good labels on each side of the shelves indicating the file names for easy identification.

If it is in your duty to have all documents placed/managed in a an order that can be retrieved and get copies whereof  easily when need, then you should devise/plan your onw numbering system for each folder and file of documents. No matter where are your files, and folder of improtant documents, you just write down your own code number or code name with subject and month on each file or folder and, make an excel created page, and paste it on your shelf.

Yea I too wanna know this.