| Protocol | Description | Specification |
|---|---|---|
| http https | HTTP/1.0 and HTTP/1.1 including Basic and Digest Authentication | RFC2616, RFC2617 |
| cid | Content-ID | RFC2111 |
| file ftp | File Transfer Protocol | RFC1808 |
| imap | IMAP | RFC2192 |
| irc | Internet Relay Chat | draft-mirashi-url-irc-01 |
| ldap | Lightweight Directory Access Protocol | RFC2255 |
| mailto | Email messages, with optional header and body parts. | RFC2368 |
| news | NNTP server access | draft-gilman-news-url-01 |
| nfs | Network File System Access | RFC2224 |
| info | GNU Info Pages | Unknown |
| man | UNIX Manual Pages | Unknown |
| rlogin telnet tn3270 | Various forms of remote shell access | RFC1738 |
| data | Directly embedded data | RFC2397 |
All of these protocols are able to be proxied by the client.