Usage of rand was replaced with arc4random (var.c, r1.17) and later documented (ksh.1, r1.70). The change was later on reverted (var.c, r1.39) back to using rand and srand_deterministic. The patch below removes the explicit mention of arc4random and documents the current behavior.
Index: ksh.1 =================================================================== RCS file: /cvs/src/bin/ksh/ksh.1,v retrieving revision 1.186 diff -u -p -r1.186 ksh.1 --- ksh.1 14 Nov 2016 06:59:42 -0000 1.186 +++ ksh.1 18 Feb 2017 18:48:53 -0000 @@ -1698,18 +1698,11 @@ Every time .Ev RANDOM is referenced, it is assigned the next random number in the range 0\-32767. -By default, -.Xr arc4random 3 -is used to produce values. If the variable .Ev RANDOM is assigned a value, the value is used as the seed to -.Xr srand 3 -and subsequent references of -.Ev RANDOM -will use -.Xr rand 3 -to produce values, resulting in a predictable sequence. +.Xr srand_deterministic 3 , +resulting in a predictable sequence. .It Ev REPLY Default parameter for the .Ic read
