In the current implementation it is only possible to fetch recommendations from the same type, e.g. articles-to-articles and images-to-images
Cross recommendations are not possible as the request parameter "itemtypeid" is defined by the content type and not by the parameter given in the reco tag.
another parameter "outputtypeid=<int-value>" should be supported and added to the reco request (see also https://confluence.ez.no/display/EZRECO/Getting+Recommendations)
The request parameter "itemtypeid" is deprecated and should be replaced by outputtypeid