NIS (formerly called Yellow Pages) allows network management of important administrative files (e.g. the password file). For more information refer to the NIS manpage and The Linux NIS(YP)/NYS/NIS+ HOWTO. There is also a book called Managing NFS and NIS by Hal Stern.
注: 此延伸不適用於 Windows 平台。
None besides functions from standard Unix libraries which are always available (either libc or libnsl, configure will detect which one to use).
以下的常數由此延伸定義，只在這個延伸被編譯成PHP或實行時期被動態載入時有效。