Q: What's the meaning of "PS: Not assigned" in ScholarOne submission system?

ADM in the ScholarOne system means “admin.” You have not mentioned if you have submitted the manuscript recently. From what I can understand from the status, your manuscript is yet to undergo the initial admin check and an editor has not been assigned yet.

I'm not really sure what “P.S.” means in the status. In a generic sense, it could be short for “post script” which is generally used to add additional information at the end of a message. I'm not really sure if it has a specific meaning in your target journal’s submission system. It’s best to contact the journal editor to have a clear understanding of the progress of your paper.

 Related reading:

• Tracking your manuscript status in journal submission systems
• PODCAST: Tracking your manuscript in the online submission system