NA

library(stringi)

## Warning: package 'stringi' was built under R version 3.1.2

locales <- stri_locale_list()
main <- locales[!stri_detect_fixed(locales, "_")]
main_col <- lapply(main, stri_opts_collator)
sorted <- lapply(main_col, function(x) stri_sort(letters, opts_collator = x))
names(sorted) <- main

simplify2array(Filter(function(x) !identical(x, letters), sorted))

##       az  ee  et  haw lt  lv 
##  [1,] "a" "a" "a" "a" "a" "a"
##  [2,] "b" "b" "b" "e" "b" "b"
##  [3,] "c" "c" "c" "i" "c" "c"
##  [4,] "d" "d" "d" "o" "d" "d"
##  [5,] "e" "e" "e" "u" "e" "e"
##  [6,] "f" "f" "f" "b" "f" "f"
##  [7,] "g" "g" "g" "c" "g" "g"
##  [8,] "h" "h" "h" "d" "h" "h"
##  [9,] "x" "x" "i" "f" "i" "i"
## [10,] "i" "i" "j" "g" "y" "y"
## [11,] "j" "j" "k" "h" "j" "j"
## [12,] "k" "k" "l" "j" "k" "k"
## [13,] "q" "l" "m" "k" "l" "l"
## [14,] "l" "m" "n" "l" "m" "m"
## [15,] "m" "n" "o" "m" "n" "n"
## [16,] "n" "o" "p" "n" "o" "o"
## [17,] "o" "p" "q" "p" "p" "p"
## [18,] "p" "q" "r" "q" "q" "q"
## [19,] "r" "r" "s" "r" "r" "r"
## [20,] "s" "s" "z" "s" "s" "s"
## [21,] "t" "t" "t" "t" "t" "t"
## [22,] "u" "u" "u" "v" "u" "u"
## [23,] "v" "v" "v" "w" "v" "v"
## [24,] "y" "w" "w" "x" "w" "w"
## [25,] "z" "y" "x" "y" "x" "x"
## [26,] "w" "z" "y" "z" "z" "z"

NA