Update Configuration.md

Configuration.md

@@ -113,7 +113,7 @@ In the DES processor operation declarations the authentication entry can be refe
 </Consumer>
 ```
   
-## Processor configuration file
+## Processors
   
   
 The DES executes concurrently a given set of *Processor* definition files that are defined in XML format.
@@ -126,9 +126,34 @@ A *Processor* configuraiton file ( *.processor_config.xml ) is the main executab
 
 The *Processor* configuration options are listed here:
 
-https://gitlab.inf.unibz.it/css-public/des_documentation/edit/master/Processors.md
+https://gitlab.inf.unibz.it/css-public/des_documentation/blob/master/Processors.md
 
+### Built-in variables
   
+In a *Processor* configuraiton some build-in parameter can be used to abstract some configurations: 
+
+The build-in parameters are replaced at runtime in all <Parameter> and in all custom tags (eg. <MyCustomTag>*$DAY*</MyCustomTag>)
+
+**$BASEPATH** The base path configured in *DES.ini*
+
+**$AOI The name of the executing *AOI*
+
+**$PROCESSOR** The name of the executing *Processor*
+
+**$CWD** The current working directory, that expands to *$BASEPATH/$AOI/$PROCESSOR*
+
+**$STAMPS_PATH** The path for Stamp files configured in DES.ini
+
+**$FILE** Iff *<FileType>* is configured, references the current File being processed (*<ProductType>* is deprecated but still valid for backward compatibility)
+
+**$YEAR** The current year
+
+**$MONTH** The current month
+
+**$DAY** The current day
+
+
+
 ## Start a DES instance ##