What is a one-stop track?
One-stop means that one party controls 100% of both the master and publishing rights. A track can still be one-stop if there are multiple rights holders but there must be a legally binding arrangement between all parties. If you are unsure, your track is not one-stop.

What is my track has multiple writers – is it one-stop?
If your track has multiple writers, they will each own a percentage of the rights (unless agreed otherwise). You should list each writer separately as a rights holder unless you have an agreement that allows you to control their percentage for Sync.