DDI Version 3.0 provides new features to document more complex studies, like collections of datasets and their relationship between themselves. The presentation will focus on the documentation of the central structure of German Socio-Economic Panel Study (SOEP), especially the linkage between the panel waves and the household/person relationship. The application of DDI 3.0 will be illustrated by selected documentation examples. As DDI 3.0 will be published in the first half of this year, this paper can only be a report on the early attempt to document complex panel studies like SOEP with DDI 3.0. The study we use is the German SOEP, a representative longitudinal study of private households in Germany which currently consists of more than 260 single datasets. It provides information on household level and on personal level over time. The Panel was started in 1984 in West Germany and was expanded as early as June 1990 to include the states of the former German Democratic Republic, even before the reunification. Some of the many topics include household composition, occupational biographies, employment, earnings, health, and satisfaction indicators. The data are available to researchers in Germany and abroad.