diff --git a/modules/04_PE_FE_parameters/iea2014/realization.gms b/modules/04_PE_FE_parameters/iea2014/realization.gms
index 68d3d7ab4bc5b58a65e5d437a55d3c41ac9076a5..ba858b8f411d7bd0098bca57992281884eda9ee3 100644
--- a/modules/04_PE_FE_parameters/iea2014/realization.gms
+++ b/modules/04_PE_FE_parameters/iea2014/realization.gms
@@ -7,6 +7,15 @@
 
 
 *' @description This realization used IEA data from 2014.
+*' The realization iea2014 serves to caliibrate the conversion efficiencies 
+*' to be consistent with predefined dataset (here iea2014, but it is flexible for up-dates). 
+*' The module realization starts with the final energy demands and then derives backwards
+*' what the secondary and primary energy demands have been. 
+*' The file datainput.gms reads in the energy data related to each process. The process related inputs are
+*' contained in input/f04_IO_input.cs4r and the output are contained in input/f04_IO_output.cs4r.
+*' These files also contain all information about existing and statistically reported joint production processes.
+*' Based on these energy flows the corresponding conversion efficiencies that replicate these energy flows.
+*' The efficiencies are assigned to the parameter pm_data(*,"eta",*).
 
 *####################### R SECTION START (PHASES) ##############################
 $Ifi "%phase%" == "sets" $include "./modules/04_PE_FE_parameters/iea2014/sets.gms"