Content from External applications can be pasted into the system. External applications include word processing and spreadsheet applications.
Content pasted from another application may contain superfluous tags. The website developer may have written code to strip most of these but some may remain. Some tags need to be cleaned manually by clicking the remove formatting button
. Some formatting will be lost and need to be reapplied.
The best method for clean content is to follow good practice and use styles in your word processing application.