Content personalization has been one of the major trends in recent Document Engineering Research. The "one docum ent for n users" paradigm is being replaced by the "one user, one document" model, where the content to be delivered to a particular user is generated by some means. This is a very promising approach for e-Government, where personalized government services, including document generation, are more and more required by users. In this paper, we introduce a method to the generation of personalized documents called Document Product Lines (DPL). DPL allows generating content in domains with high variability and with high levels of reuse. We describe the basic principles underlying DPL and show its application to the e-Government field using the personalized tax statement as case study.