o Remove meaningless PROTOCOLS section. o Describe passing file descriptors as separate section.   - Descriptors can be passed through any protocol of the UNIX family,     not SOCK_STREAM and SOCK_SEQPACKET only. [1] o Describe socket options as separate section.   - Move LOCAL_PEERCRED option to this section.   - Describe struct xucred.   - In LOCAL_CREDS section mention that credentials     are passed only on the first read on non-datagram     sockets. o Xref all mentioned system calls.
o Remove meaningless PROTOCOLS section.
o Describe passing file descriptors as separate section.
  - Descriptors can be passed through any protocol of the UNIX family,
    not SOCK_STREAM and SOCK_SEQPACKET only. [1]
o Describe socket options as separate section.
  - Move LOCAL_PEERCRED option to this section.
  - Describe struct xucred.
  - In LOCAL_CREDS section mention that credentials
    are passed only on the first read on non-datagram
    sockets.
o Xref all mentioned system calls.

Noticed by:	Igor Sysoev [1]

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