dirty file indicator

This has nothing to do with any lewd content! It’s an indicator, usually an asterisk (*), at the beginning or ending of a filename displayed while you are editing the file that indicates that changes have been made and it hasn’t been saved yet. It’s helpful to know when you need to save your work or if you’re just looking at a file, if an inadvertent change was made. Dirty files are incomplete, clean files are saved and complete.