| AF_APPLETALK | Address family Appletalk DDP | 
| AF_ASH | Address family: Ash | 
| AF_ATMPVC | Address family: ATM PVCs | 
| AF_ATMSVC | Address family: ATM SVCs | 
| AF_AX25 | Address family Amateur Radio AX.25 | 
| AF_BLUETOOTH | Address family: Bluetooth sockets | 
| AF_BRIDGE | Address family Multiprotocol bridge | 
| AF_DECnet | Address family: Reserved for DECnet project. | 
| AF_ECONET | Address family: Acorn Econet | 
| AF_INET | Address family Internet IP Protocol | 
| AF_INET6 | Address family IP version 6 | 
| AF_IPX | Address family Novell IPX | 
| AF_IRDA | Address family: IRDA sockets | 
| AF_KEY | Address family: PF_KEY key management API | 
| AF_LLC | Address family: Linux LLC | 
| AF_LOCAL | Address family: Unix socket | 
| AF_MAX | Address family Maximum value | 
| AF_NETBEUI | Address family:  Reserved for 802.2LLC project | 
| AF_NETLINK | Address family: ? | 
| AF_NETROM | Address family Amateur radio NetROM | 
| AF_PACKET | Address family: Packet family | 
| AF_PPPOX | Address family: PPPoX sockets | 
| AF_ROSE | Address family: Amateur Radio X.25 PLP | 
| AF_ROUTE | Address family: Alias to emulate 4.4BSD. | 
| AF_SECURITY | Address family: Security callback pseudo AF | 
| AF_SNA | Address family: Linux SNA project | 
| AF_TIPC | Address family: TIPC sockets | 
| AF_UNIX | Address family Unix domain sockets | 
| AF_UNSPEC | Address family Not specified | 
| AF_WANPIPE | Address family: Wanpipe API Sockets | 
| AF_X25 | Address family Reserved for X.25 project | 
| EsockADDRINUSE | Error number when socket address is already in use | 
| EsockEACCESS | Access forbidden error | 
| EsockEBADF | Alias: bad file descriptor | 
| EsockEFAULT | Alias: an error occurred | 
| EsockEINTR | Alias : operation interrupted | 
| EsockEINVAL | Alias: Invalid value specified | 
| EsockEMFILE | Error code ? | 
| EsockEMSGSIZE | Wrong message size error | 
| EsockENOBUFS | No buffer space available error | 
| EsockENOTCONN | Not connected error | 
| EsockENOTSOCK | File descriptor is not a socket error | 
| EsockEPROTONOSUPPORT | Protocol not supported error | 
| EsockEWOULDBLOCK | Operation would block error | 
| INADDR_ANY | A bitmask matching any IP address on the local machine. | 
| INADDR_NONE | A bitmask matching no valid IP address | 
| IPPROTO_AH | authentication header. | 
| IPPROTO_COMP | Compression Header Protocol. | 
| IPPROTO_DSTOPTS | IPv6 destination options. | 
| IPPROTO_EGP | Exterior Gateway Protocol. | 
| IPPROTO_ENCAP | Encapsulation Header. | 
| IPPROTO_ESP | encapsulating security payload. | 
| IPPROTO_FRAGMENT | IPv6 fragmentation header. | 
| IPPROTO_GRE | General Routing Encapsulation. | 
| IPPROTO_HOPOPTS | IPv6 Hop-by-Hop options. | 
| IPPROTO_ICMP | Internet Control Message Protocol. | 
| IPPROTO_ICMPV6 | ICMPv6. | 
| IPPROTO_IDP | XNS IDP protocol. | 
| IPPROTO_IGMP | Internet Group Management Protocol. | 
| IPPROTO_IP | Dummy protocol for TCP. | 
| IPPROTO_IPIP | IPIP tunnels (older KA9Q tunnels use 94). | 
| IPPROTO_IPV6 | IPv6 header. | 
| IPPROTO_MAX | Maximum value for IPPROTO options | 
| IPPROTO_MTP | Multicast Transport Protocol. | 
| IPPROTO_NONE | IPv6 no next header. | 
| IPPROTO_PIM | Protocol Independent Multicast. | 
| IPPROTO_PUP | PUP protocol. | 
| IPPROTO_RAW | Raw IP packets. | 
| IPPROTO_ROUTING | IPv6 routing header. | 
| IPPROTO_RSVP | Reservation Protocol. | 
| IPPROTO_SCTP | Stream Control Transmission Protocol. | 
| IPPROTO_TCP | Transmission Control Protocol. | 
| IPPROTO_TP | SO Transport Protocol Class 4. | 
| IPPROTO_UDP | User Datagram Protocol. | 
| IPV6_ADDRFORM | Change the IPV6 address into a different address family. Deprecated | 
| IPV6_ADD_MEMBERSHIP | Undocumented Getsockopt option ? | 
| IPV6_AUTHHDR | GetSockOpt/SetSockopt: Deliver authentication header messages | 
| IPV6_CHECKSUM | Undocumented Getsockopt option ? | 
| IPV6_DROP_MEMBERSHIP | Undocumented Getsockopt option ? | 
| IPV6_DSTOPTS | Deliver destination option control messages | 
| IPV6_HOPLIMIT | Deliver an integer containing the HOP count | 
| IPV6_HOPOPTS | Deliver hop option control messages | 
| IPV6_IPSEC_POLICY | Undocumented Getsockopt option ? | 
| IPV6_JOIN_ANYCAST | Undocumented Getsockopt option ? | 
| IPV6_JOIN_GROUP | GetSockOpt/SetSockopt: Control membership (join group) in multicast groups | 
| IPV6_LEAVE_ANYCAST | Undocumented Getsockopt option ? | 
| IPV6_LEAVE_GROUP | GetSockOpt/SetSockopt: Control membership (leave group)in multicast groups | 
| IPV6_MTU | GetSockOpt/SetSockopt: Get/Set the MTU for the socket | 
| IPV6_MTU_DISCOVER | GetSockOpt/SetSockopt: Get/Set Control path MTU Discovery on the socket | 
| IPV6_MULTICAST_HOPS | GetSockOpt/SetSockopt: Get/Set the multicast hop limit. | 
| IPV6_MULTICAST_IF | GetSockOpt/SetSockopt: Get/Set device for multicast packages on the socket. | 
| IPV6_MULTICAST_LOOP | GetSockOpt/SetSockopt: Control whether socket sees multicast packages that it has sent itself | 
| IPV6_NEXTHOP | sendmsg: set next hop for IPV6 datagram | 
| IPV6_PKTINFO | Change delivery options for incoming IPV6 datagrams | 
| IPV6_PKTOPTIONS | Undocumented Getsockopt option ? | 
| IPV6_PMTUDISC_DO | Always DF. | 
| IPV6_PMTUDISC_DONT | Never send DF frames. | 
| IPV6_PMTUDISC_WANT | Use per route hints. | 
| IPV6_RECVERR | GetSockOpt/SetSockopt: Control receiving of asynchronous error options | 
| IPV6_ROUTER_ALERT | GetSockOpt/SetSockopt: Get/Set Pass all forwarded packets containing router alert option | 
| IPV6_RTHDR | Deliver routing header control messages | 
| IPV6_RTHDR_LOOSE | Hop doesn't need to be neighbour. | 
| IPV6_RTHDR_STRICT | Hop must be a neighbour. | 
| IPV6_RTHDR_TYPE_0 | IPv6 Routing header type 0. | 
| IPV6_RXDSTOPTS | Undocumented Getsockopt option ? | 
| IPV6_RXHOPOPTS | Undocumented Getsockopt option ? | 
| IPV6_RXSRCRT | Undocumented Getsockopt option ? | 
| IPV6_UNICAST_HOPS | GetSockOpt/SetSockopt: Get/Set unicast hop limit | 
| IPV6_V6ONLY | GetSockOpt/SetSockopt: Handle IPV6 connections only | 
| IPV6_XFRM_POLICY | Undocumented Getsockopt option ? | 
| IP_ADD_MEMBERSHIP | add an IP group membership | 
| IP_ADD_SOURCE_MEMBERSHIP | join source group | 
| IP_BLOCK_SOURCE | block data from source | 
| IP_DEFAULT_MULTICAST_LOOP | Undocumented ? | 
| IP_DEFAULT_MULTICAST_TTL | Undocumented ? | 
| IP_DROP_MEMBERSHIP | drop an IP group membership | 
| IP_DROP_SOURCE_MEMBERSHIP | leave source group | 
| IP_HDRINCL | Header is included with data. | 
| IP_MAX_MEMBERSHIPS | Maximum group memberships for multicast messages | 
| IP_MSFILTER | Undocumented ? | 
| IP_MTU_DISCOVER | Undocumented ? | 
| IP_MULTICAST_IF | set/get IP multicast i/f | 
| IP_MULTICAST_LOOP | set/get IP multicast loopback | 
| IP_MULTICAST_TTL | set/get IP multicast ttl | 
| IP_OPTIONS | IP per-packet options. | 
| IP_PKTINFO | Undocumented ? | 
| IP_PKTOPTIONS | Undocumented ? | 
| IP_PMTUDISC | Undocumented ? | 
| IP_PMTUDISC_DO | Always DF. | 
| IP_PMTUDISC_DONT | Never send DF frames. | 
| IP_PMTUDISC_WANT | Use per route hints. | 
| IP_RECVERR | Undocumented ? | 
| IP_RECVOPTS | Receive all IP options w/datagram. | 
| IP_RECVRETOPTS | Receive IP options for response. | 
| IP_RECVTOS | Undocumented ? | 
| IP_RECVTTL | Undocumented ? | 
| IP_RETOPTS | Set/get IP per-packet options. | 
| IP_ROUTER_ALERT | Undocumented ? | 
| IP_TOS | IP type of service and precedence. | 
| IP_TTL | IP time to live. | 
| IP_UNBLOCK_SOURCE | unblock data from source | 
| MCAST_BLOCK_SOURCE | block from given group | 
| MCAST_EXCLUDE | Undocumented ? | 
| MCAST_INCLUDE | Undocumented ? | 
| MCAST_JOIN_GROUP | join any-source group | 
| MCAST_JOIN_SOURCE_GROUP | join source-spec gruoup | 
| MCAST_LEAVE_GROUP | leave any-source group | 
| MCAST_LEAVE_SOURCE_GROUP | leave source-spec group | 
| MCAST_MSFILTER | Undocumented ? | 
| MCAST_UNBLOCK_SOURCE | unblock from given group | 
| MSG_CONFIRM | Send flags: Conform connection | 
| MSG_CTRUNC | Receive flags: Control Data was discarded (buffer too small) | 
| MSG_DONTROUTE | Send flags: don't use gateway | 
| MSG_DONTWAIT | Receive flags: Non-blocking operation request. | 
| MSG_EOF | Alias for MSG_FIN | 
| MSG_EOR | Receive flags: End of record | 
| MSG_ERRQUERE | Receive flags: ? | 
| MSG_FIN | Receive flags: ? | 
| MSG_MORE | Receive flags: ? | 
| MSG_NOSIGNAL | Receive flags: Suppress SIG_PIPE signal. | 
| MSG_OOB | Receive flags: receive out-of-band data. | 
| MSG_PEEK | Receive flags: peek at data, don't remove from buffer. | 
| MSG_PROXY | Receive flags: ? | 
| MSG_RST | Receive flags: ? | 
| MSG_SYN | Receive flags: ? | 
| MSG_TRUNC | Receive flags: packet Data was discarded (buffer too small) | 
| MSG_TRYHARD | Receive flags: ? | 
| MSG_WAITALL | Receive flags: Wait till operation completed. | 
| NoAddress | Constant indicating invalid (no) network address. | 
| NoAddress6 | Constant indicating invalid (no) IPV6 network address. | 
| NoNet | Constant indicating invalid (no) network address. | 
| NoNet6 | Constant indicating invalid (no) IPV6 network address. | 
| PF_APPLETALK | Protocol family: Appletalk DDP | 
| PF_ASH | Protocol family: Ash | 
| PF_ATMPVC | Protocol family: ATM PVCs | 
| PF_ATMSVC | Protocol family:  ATM SVCs | 
| PF_AX25 | Protocol family: Amateur Radio AX.25 | 
| PF_BLUETOOTH | Protocol family: Bluetooth sockets | 
| PF_BRIDGE | Protocol family: Multiprotocol bridge | 
| PF_DECnet | Protocol Family: DECNET project | 
| PF_ECONET | Protocol family: Acorn Econet | 
| PF_INET | Protocol family: Internet IP Protocol | 
| PF_INET6 | Protocol family: IP version 6 | 
| PF_IPX | Protocol family: Novell IPX | 
| PF_IRDA | Protocol family: IRDA sockets | 
| PF_KEY | Protocol family: Key management API | 
| PF_LLC | Protocol family: Linux LLC | 
| PF_LOCAL | Protocol family: Unix socket | 
| PF_MAX | Protocol family: Maximum value | 
| PF_NETBEUI | Protocol family: Reserved for 802.2LLC project | 
| PF_NETLINK | Protocol family: ? | 
| PF_NETROM | Protocol family:Amateur radio NetROM | 
| PF_PACKET | Protocol family: Packet family | 
| PF_PPPOX | Protocol family: PPPoX sockets | 
| PF_ROSE | Protocol family: Amateur Radio X.25 PLP | 
| PF_ROUTE | Protocol Family: ? | 
| PF_SECURITY | Protocol family: Security callback pseudo PF | 
| PF_SNA | Protocol Family: Linux SNA project | 
| PF_TIPC | Protocol family: TIPC sockets | 
| PF_UNIX | Protocol family: Unix domain sockets | 
| PF_UNSPEC | Protocol family: Unspecified | 
| PF_WANPIPE | Protocol family: Wanpipe API Sockets | 
| PF_X25 | Protocol family: Reserved for X.25 project | 
| SCM_SRCRT | Undocumented Getsockopt option ? | 
| SCM_TIMESTAMP | Socket option: ? | 
| SHUT_RD | Shutdown read part of full duplex socket | 
| SHUT_RDWR | Shutdown read and write part of full duplex socket | 
| SHUT_WR | Shutdown write part of full duplex socket | 
| SOCK_DGRAM | Type of socket: datagram (conn.less) socket (UDP) | 
| SOCK_MAXADDRLEN | Maximum socket address length for Bind  call. | 
| SOCK_RAW | Type of socket:  raw socket | 
| SOCK_RDM | Type of socket: reliably-delivered message | 
| SOCK_SEQPACKET | Type of socket: sequential packet socket | 
| SOCK_STREAM | Type of socket: stream (connection) type socket (TCP) | 
| SOL_ICMPV6 | Socket level values for IPv6: ICMPV6 | 
| SOL_IP | Undocumented ? | 
| SOL_IPV6 | Socket level values for IPv6: IPV6 | 
| SOL_SOCKET | Socket option level: Socket level | 
| SOMAXCONN | Maximum queue length specifiable by listen. | 
| SO_ACCEPTCONN | Socket option: ? | 
| SO_ATTACH_FILTER | Socket option: ? | 
| SO_BINDTODEVICE | Socket option: ? | 
| SO_BROADCAST | Socket option: Broadcast | 
| SO_BSDCOMPAT | Socket option: ? | 
| SO_DEBUG | Socket option level: debug | 
| SO_DETACH_FILTER | Socket option: ? | 
| SO_DONTROUTE | Socket option: Don't route | 
| SO_ERROR | Socket option: Error | 
| SO_KEEPALIVE | Socket option: keep alive | 
| SO_LINGER | Socket option: ? | 
| SO_NO_CHECK | Socket option: ? | 
| SO_OOBINLINE | Socket option: ? | 
| SO_PASSCRED | Socket option: ? | 
| SO_PEERCRED | Socket option: ? | 
| SO_PEERNAME | Socket option: ? | 
| SO_PRIORITY | Socket option: ? | 
| SO_RCVBUF | Socket option: receive buffer | 
| SO_RCVLOWAT | Socket option: ? | 
| SO_RCVTIMEO | Socket option: ? | 
| SO_REUSEADDR | Socket option: Reuse address | 
| SO_REUSEPORT |  | 
| SO_SECURITY_AUTHENTICATION | Socket option: ? | 
| SO_SECURITY_ENCRYPTION_NETWORK | Socket option: ? | 
| SO_SECURITY_ENCRYPTION_TRANSPORT | Socket option: ? | 
| SO_SNDBUF | Socket option: Send buffer | 
| SO_SNDLOWAT | Socket option: ? | 
| SO_SNDTIMEO | Socket option: ? | 
| SO_TIMESTAMP | Socket option: ? | 
| SO_TYPE | Socket option: Type | 
| S_IN | Input socket in socket pair. | 
| S_OUT | Output socket in socket pair | 
| TCP_CONGESTION | Get/set  the  congestion-control algorithm for this socket | 
| TCP_CORK | Get/Set CORK algorithm: Send only complete packets | 
| TCP_DEFER_ACCEPT | Get/Set deferred accept on server socket | 
| TCP_INFO | Get TCP connection information (Linux only) | 
| TCP_KEEPCNT | Get/Set retry count for unacknowledged KEEPALIVE transmissions. | 
| TCP_KEEPIDLE | Get/Set inactivity interval between KEEPALIVE transmissions. | 
| TCP_KEEPINTVL | Get/Set retry interval for unacknowledged KEEPALIVE transmissions. | 
| TCP_LINGER2 | Get/Set Linger2 flag | 
| TCP_MAXSEG | Get/Set Maximum segment size | 
| TCP_MD5SIG | Get/Set TCP MD5 signature option | 
| TCP_NODELAY | Get/Set No delay flag: disable Nagle algorithm | 
| TCP_QUICKACK | Get/Set quick ACK packet option. | 
| TCP_SYNCNT | Get/Set number of SYN packets to send before giving up on connection establishment | 
| TCP_WINDOW_CLAMP | Get/Set maximum packet size | 
| UDP_CORK | Get/Set UDP CORK algorithm on datagram sockets | 
| UDP_ENCAP | Get/Set UDP encapsulation flag for IPSec datagram sockets | 
| UDP_ENCAP_ESPINUDP | ?  Undocumented datagram option, IPSec related | 
| UDP_ENCAP_ESPINUDP_NON_IKE | ? Undocumented datagram option, IPSec related | 
| UDP_ENCAP_L2TPINUDP | ?  Undocumented datagram option, IPSec related |