The ArcPy - function "ListFeatureClasses" saves the list of features in a specific coding. E.g.:
fc = ['uRoadL', ...]
ListFeatureClasses—ArcPy Functions | ArcGIS for Desktop
Some tools, e.g. Calculate Visual Specification" can't work with such list. The coding of the list must be changed before. That is why it would be helpfull if the programmer of the python-script could choose the coding with an additional parameter.