diff --git a/RBBGCMuso/R/outputMapping.R b/RBBGCMuso/R/outputMapping.R
index 4c3bbc6..230afd0 100644
--- a/RBBGCMuso/R/outputMapping.R
+++ b/RBBGCMuso/R/outputMapping.R
@@ -1,6 +1,6 @@
 #' updateMusoMapping
 #'
-#' This function updates the Biome-BGCMuSo output code-variable matrix. Within Biome-BGCMuSo the state variables and fluxes are marked by integer numbers. In order to provide meaningful variable names (e.g. 3009 means Gross Primary Production in Biome-BGCMuSo v5) a conversion table is needed which is handled by this function. 
+#' This function updates the Biome-BGCMuSo output code-variable matrix (creates a json file that is used internally by RBBGCMuso). Within Biome-BGCMuSo the output state variablesare marked by integer numbers (see the User's Guide). In order to provide meaningful variable names (e.g. 3009 means Gross Primary Production) a conversion table is needed which is handled by this function. The input Excel file must have the following column order: name, index, units, description (plus other optional columns line group). name refers to the abbreviation of the variable; index is the integer number of the output variable; unit is the unit of the variable; description is a meaningful text to explain the variable. The script will NOT work with other column order!
 #' @author Roland HOLLOS
 #' @param excelName Name of the excelfile which contains the parameters 
 #' @importFrom openxlsx read.xlsx