A request letter is a document written for the intention of requesting from an entity for particular pieces of information, permission or favor for a certain matter. (template.net)
One thing that's been fascinating to watch over past few months has been the flare - up of brief discussions among both friends and strangers related to particular pieces of information posted on Facebook — usually a status update, but sometimes an event or profile wall comment. (epolitics.com)
Once added, they can not be modified or deleted, ensuring a permanent record of a particular piece of information existing in a certain form at a certain time. (canadianbusiness.com)