It is generally recognized that the common non-terminal labels for syntactic constituents (NP, VP, etc.) do not exhaust the syntactic and semantic information one would like about parts of a syntactic tree. For example, the Penn Tree-bank gives each constituent zero or more `function tags' indicating semantic roles and other related information not easily encapsulated in the simple constituent labels. We present a statistical algorithm for assigning these function tags that, on text already parsed to a simple-label level, achieves an F-measure of 87%, which rises to 99% when considering `no tag' as a valid choice.