"...[T]he NKJV translators put in the footnotes of the study
editions the corrupt Critical or Minority Text of Westcott and Hort (from which
the corrupt Modern EnglishVersions are derived). It is identified as “NU.” The
“N” stands for the Nestle-Aland text. The “U” stands for the United Bible
Society text. Both of these texts are dependent largely on the corrupt Vatican
and Sinai manuscripts, virtually the same as the Westcott and Hort Greek text of
1881."
Quote source:
http://www.biblefortoday.org/PDF/dkjb_appendix.pdf