How does the port reservation work?

[H2000Y 0]

I'm wanting to forward a port to " 5029 " but I keep getting a message that it's reserved. Do I need to make a reservation? Am I unable to forward this port? I'm wanting to host a server under this port but i'm unable to. Is it one user at a time?

[benfitita 35]

Yes, only one user can have a particular port assigned to them. You'll most likely need to use another port. Usually it's possible to provide a custom port in client software.