Automated Web service composition and automated Web service annotation could be seen as complimentary methodologies. While automated annotation allows to extract Web service semantics from existing WSDL documents, automated composition uses this semantics for integrating applications. Therefore applicability of both methodologies is essential for increasing the productivity of information system integration. Although several papers have proposed methods for automated annotation, there is a lack of studies providing analysis of the general structure of Web services. We argue that having an overview of general Web services structures would greatly improve design of new annotation methods. At the same time, progress in automated composition has resulted in several methods for automating Web services orchestration. In this paper we propose application of automated composition also for analysing Web services domain. We identify and analyse some general Web services properties and provide th...