(sort invocation): -d now overrides -i.

"whitespace" -> "blanks"; "whitespace" isn't correct.
-t '\0' now specifies a NUL tab.

doc/coreutils.texi

@@ -2969,6 +2969,8 @@ converting to floating point.
 @vindex LC_CTYPE
 Ignore nonprinting characters.
 The @env{LC_CTYPE} locale determines character types.
+This option has no effect if the stronger @option{--dictionary-order}
+(@option{-d}) option is also given.
 
 @item -M
 @itemx --month-sort
@@ -2976,7 +2978,7 @@ The @env{LC_CTYPE} locale determines character types.
 @opindex --month-sort
 @cindex months, sorting by
 @vindex LC_TIME
-An initial string, consisting of any amount of whitespace, followed
+An initial string, consisting of any amount of blanks, followed
 by a month name abbreviation, is folded to UPPER case and
 compared in the order @samp{JAN} < @samp{FEB} < @dots{} < @samp{DEC}.
 Invalid names compare low to valid names.  The @env{LC_TIME} locale
@@ -2989,7 +2991,7 @@ category determines the month spellings.
 @cindex numeric sort
 @vindex LC_NUMERIC
 Sort numerically: the number begins each line; specifically, it consists
-of optional whitespace, an optional @samp{-} sign, and zero or more
+of optional blanks, an optional @samp{-} sign, and zero or more
 digits possibly separated by thousands separators, optionally followed
 by a decimal-point character and zero or more digits.  The @env{LC_NUMERIC}
 locale specifies the decimal-point character and thousands separator.
@@ -3085,7 +3087,7 @@ than @var{size}.
 @cindex field separator character
 Use character @var{separator} as the field separator when finding the
 sort keys in each line.  By default, fields are separated by the empty
-string between a non-whitespace character and a whitespace character.
+string between a non-blank character and a blank character.
 That is, given the input line @w{@samp{ foo bar}}, @command{sort} breaks it
 into fields @w{@samp{ foo}} and @w{@samp{ bar}}.  The field separator is
 not considered to be part of either the field preceding or the field
@@ -3093,6 +3095,10 @@ following.  But note that sort fields that extend to the end of the line,
 as @option{-k 2}, or sort fields consisting of a range, as @option{-k 2,3},
 retain the field separators present between the endpoints of the range.
 
+To specify a zero byte (@acronym{ASCII} @sc{nul} (Null) character) as
+the field separator, use the two-character string @samp{\0}, e.g.,
+@samp{sort -t '\0'}.
+
 @item -T @var{tempdir}
 @itemx --temporary-directory=@var{tempdir}
 @opindex -T
@@ -3218,7 +3224,7 @@ field-end part of the key specifier.
 
 @item
 Sort the password file on the fifth field and ignore any
-leading white space.  Sort lines with equal values in field five
+leading blanks.  Sort lines with equal values in field five
 on the numeric user ID in field three.
 
 @example
@@ -3242,7 +3248,7 @@ The use of @option{-print0}, @option{-z}, and @option{-0} in this case means
 that pathnames that contain Line Feed characters will not get broken up
 by the sort operation.
 
-Finally, to ignore both leading and trailing white space, you
+Finally, to ignore both leading and trailing blanks, you
 could have applied the @samp{b} modifier to the field-end specifier
 for the first key,