diff --git a/jdr/sheet.go b/jdr/sheet.go
index 277fcfa..e3bf370 100644
--- a/jdr/sheet.go
+++ b/jdr/sheet.go
@@ -158,12 +158,18 @@ func (n *xmlNode) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
 	return d.DecodeElement((*node)(n), &start)
 }
 
+// The parseVariable function parses a Variable value from a XML node.
+// The variable type is inferred from the "type" attribute of the node.
+// If this attribute is omitted, the type of the variable must be given through the
+// "defaults" parameter to avoid a parsing error.
+// If this attribute is specified, the "defaults" parameter will be unused and may be nil
 func parseVariable(root xmlNode, sheet *CharacterSheet, defaults *Variable) (*Variable, error) {
 	ret := &Variable{}
 
 	typeOk := false
 	nameOk := false
 
+	//parsing default values
 	if defaults != nil {
 		switch defaults.Type.(type) {
 		case *VariableType_badType:
@@ -174,6 +180,7 @@ func parseVariable(root xmlNode, sheet *CharacterSheet, defaults *Variable) (*Va
 		}
 	}
 
+	//iterating on the attributes
 	for i := 0; i < len(root.Attrs); i++ {
 		attrName := root.Attrs[i].Name.Local
 		attrVal := root.Attrs[i].Value
@@ -192,6 +199,7 @@ func parseVariable(root xmlNode, sheet *CharacterSheet, defaults *Variable) (*Va
 		}
 	}
 
+	//check if no parse error
 	if !nameOk {
 		return nil, errors.New("Unnamed variable")
 	}