What do you mean by "additional information"? You can add a label, either by setting the standard script label:
myPageItem.label = "Some info";
which is quick and handy but inflexible, or you could use insertLabel(), which allows you to set any number of labels:
myPageItem.insertLabel ("shape", "circle");
myPageItem.insertLabel ("purpose", "globe");
Is that what you're after?
thanx for your answer.
This already looks good. But under which attribute of the pageItem can I later read the set labels? The label itself is only a string...
label = myPageItem.extractLabel(key);