Copy-and-paste is only part of the story. Managing subdocuments in a digital library extends copy-and-paste with new possibilities.

• Would you like to have citations be automatic?
• Do you want to automatically recall original sources for review and further use?
• Would it be useful to "copy" now, save the item, and "paste" it later?
• Is remembering where else you have "pasted" an item important, for example so you don't inadvertently re-use exam questions too often?

Citation count is often a factor in promotion or salary determination. Subdocument management can help with this.

• Do you want to know where, and how often, parts of your work are referenced?
• Would it be useful to have other users select portions of your work for their use?
• Would you benefit from readers having the ability to select portions of your work and annotate them?

Discourse, whether through blogs or e-mail, can be made easier and more authoritative by the inclusion of cited subdocuments selected from library works.