Sometimes RUM is enabled but tagging users is not allowed for privacy reasons. And you would like to monitor your user actions in target web application but only yours, others must be still anonymous.
If you are in that situation:
That session will be tagged with your input tag. It might be helpful for testing or discovery or troubleshooting purposes.
I hope it could help!
Always appreciable this type of sharing. In addition, here is the link detailing a complete list of these JS API functions.
A more fleshed out tip, if you want to follow a specific user click (here click button "soumettre: ", possibility to change in the JS application code (requires the development team) as follows:
action = dtrum.enterAction("soumettre:" + caseName);