Traction® TeamPage™ and Communicator™ Features ("Enterprise Blog Software"):

"You can create any number of category labels in each project. The labels from one project may be applied to content in any other project. Labels may be applied at the article level, or on individual paragraphs to call out key information buried in text.

Traction keeps a record of all label changes so, for example, you can track when a paragraph labeled "To Do" label was relabeled Done. This facility also lets you evolve a taxonomy over time, changing labels as needed; Traction lets you rewind the labels to reflect any point or period in time.

[...] Traction is a true journaling technology, with best of class audit trail capability. The audit trail includes a full trail of all posts, edits, comments, label changes, emails sent out, and other activities. It's possible to look at Traction from any time period or perspective. Attachments are maintained in the WebDAV document store and may be versioned selectively or you can set mandatory versioning."