Personally, you can call your PC anything you want. But in Windows 10, it has to go by with a unique name so that it can be identified and communicate with other devices in a network.
Having two PCs with the same name in a network creates a conflict for network communications.
Most PCs come with default names, but you can easily change the name to anything short and sweet, something under 15 characters or less. Standard characters like number from 0 to 9, upper and lowercase letters from A through Z, and a hyphen (-) are best suited for this.
PC names cannot consist entirely of numbers, nor can they contain spaces. And yes, special characters are not allowed, characters like @ / < > $ % and such.
You can rename your PC in Windows 10 using either the Settings app, or in System Properties.
The Settings app, first.
1. Open Settings.
2. Go to System, and then About towards the end.
3. Click on the Rename this PC button, and Windows will open up a small window that will allow you to enter a new name for your computer. You will need to restart your device to have the new PC name applied, so be sure to save and close anything you have open first.
This can also be accomplished from System Properties.
1. Fire up Control Panel.
2. Make sure you are in the Icons view, and then click on the System icon.
3. In the panel that opens up, click on the Advanced system settings link on the left. This will open up another window, with a few different tabs.
4. Go to the Computer Name tab, and click on the Change button.
5. Here type a new name for your PC, click on OK, and then restart your device when prompted to have the new name reflected throughout the operating system and any networks your computer is in.