This is an extension to the tree editor TrEd (http://ufal.mff.cuni.cz/tred/). Extensions are described here: http://ufal.mff.cuni.cz/tred/documentation/ar01s17.html It allows to visualise and search for multiword-expressions and named entities (or anything else that somebody annotates) in the PML st-files. st-files contain additional annotations on top of t-layer of PDT 2.0 (http://ufal.mff.cuni.cz/pdt2.0/).