Recoding was not carried out.
The category "obligatory" (code 1) contains around 80 percent of the population.
This seems far to high, and is not comparable to the frequency distribution of the Microsensus for 1995.

If LIS users want to pursue a recode they may do so on their own responsability.
The mapping below may serve as suggestion. 

PEDUC							     ISCED97	   LIS recode
  1 obligatory									1
  3 vocational middle school							2
  4 general high school								2
  5 vocational high school							2
  6 university									3