Well-constructed IKMSs share a number of common features including ease of use, ease of navigation, security, indexing and searching, automatic HTML conversion, document version tracking, platform independence, ease of access and notification. A robust knowledge management system allows users to store and retrieve both digital documents and paper-based documents or notes that have been scanned into the system. An IKMS should allow users to upload documents into the central document repository using a number of methods. Document management systems also can be used to facilitate collaboration of groups on a project.