In OS X, Apple supports the configuration of various network proxy servers for individual ports in its Network system preferences. In some instances users have been reporting odd formatting issues in which entered proxy port settings either adopt commas or decimal points, though the proxy settings still work just fine.
As with most network services, proxy settings require a specific communications port to be set so network traffic can be directed to the appropriate background tasks that require it. In many cases such as Web browsing (port 80) or FTP access (port 21) these ports are fairly well established and assumed; however, for other services network administrators may have special ports set up that you need to configure manually.
For proxy servers, these ports are set in the Network system preferences by selecting a connection (such as Wi-Fi or Ethernet), and then clicking the Advanced button. In the panel that appears, choosing the Proxy tab will display a list of configurable options, including Web and Secure Web proxies, FTP, and SOCKS proxies.
For most of these services you are required to enter a server address and a port number for the connection. When you enter a port number and it is longer than three digits, if you save the settings and reopen them you will see the number formatted with a comma or period to indicate the thousands separator.
This is an unconventional and perhaps confusing representation of port numbers; however, it seems to simply be an interface bug.
The value of the port field is properly used and proxy settings will continue to function, but it appears a programmer set the text field to format the number instead of displaying it as a basic number string. Therefore, if you see this in your settings then do not be alarmed, as it will still work properly. Apple will likely address the problem in a future update to OS X.
Special thanks to MacFixIt reader Marcel for writing in about this.