In package data.table version 1.9.5 when I check if the variable is within the specified limits, but any value of variable don't exist and print out all data.table.

Example:
Package data.table version 1.9.5:

library(data.table)
d <- data.table(a=c("A2","A4","A2"))
d[, sert:=""]
d[a %in% c("BE", "BD"), sert:="11"]
a sert
1: A2
2: A4
3: A2

str(d)
Classes ‘data.table’ and 'data.frame': 3 obs. of 2 variables:
$ a : chr "A2" "A4" "A2"
$ sert: chr "" "" ""

• attr(*, ".internal.selfref")=
• attr(, "index")= atomic
  ..- attr(, "__a")= int 1 3 2