Identifies a known URL scheme
| Name | Description |
|---|---|
| none | Indicates that no scheme is present |
| unknown | Indicates the scheme is not a well-known scheme |
| ftp | File Transfer Protocol (FTP) |
| file | File URI Scheme |
| http | The Hypertext Transfer Protocol URI Scheme |
| https | The Secure Hypertext Transfer Protocol URI Scheme |
| ws | The WebSocket URI Scheme |
| wss | The Secure WebSocket URI Scheme |