You may have experienced this:
You connect to a Windows Terminal Server, or remote Windows desktop using MSTSC.EXE from your Windows 8.1 system, and your local client printer(s) do not show up on the remote host as expected.
First, on the local computer, make sure that you have selected to share your printers during the session by editing the settings for the current MSTSC session.
On the remote host, while connected, go to the add-printer wizard, and choose to install a new local printer. When asked to chooses a port, if you scroll down the list of available ports you will see terminal server (TS) ports. The ACTIVE ones only will be assigned numbers with the prefix PRN. These will appear like this: PRN2, PRN3, PRN4, PRNx, PRNy, etc etc.
Choose one of the PRN ports that is not assigned to a device. Then continue the install, selecting or downloading the correct printer driver. When finished choose to print a test page. If it prints, then you picked the right PRN port.
If it didn't print, open the printer properties (right-click --> printer properties). On the advanced tab, choose a different PRN port, and try the test page again from the general tab. Repeat this until the test page prints.
No, there's no other way to know the correct PRN port, but this will get you there eventually.