1. A computer-implemented method, comprising: establishing a set of user selected eXtensible Markup Language (XML) tags and a set of candidate XML tags; and for a candidate XML tag in said set of candidate XML tags: determining, based on a collection of XML documents, a ranking measure for said candidate XML tag, said ranking measure reflecting a rank of said candidate XML tag relative to other candidate XML tags of said set of candidate XML tags; wherein said ranking measure for said candidate XML tag in said set of candidate XML tags is determined based on a real-time analysis measure value that is determined based on co-locations of said candidate XML tag and one or more user selected XML tags of said set of user selected XML tags in one or more XML documents of said collection of XML documents; and storing first data that, for said candidate XML tag in said set of candidate XML tags, associates said candidate XML tag with said ranking measure.