Step 1:  Click on the 'Settings' icon for the desired file. 


Step 2:  Click the 'Tags' section, enter a custom tag and hit return to save. You can create multiple tags per file.



Step 3:  Saved tags appear as suggestions when tagging other files.


Step 4:  Search for tagged files by clicking the 'Search' icon in the upper right corner of the console.


Step 5:  Tagged files show.