In this paper we examine some problems related to capturing the structure and the topic name space of learning content in the context of Topic Map authoring. We demonstrate that the use of traditional course taxonomies as ontological resources is problematic. Based on these findings and on the results of a locally conducted study, we propose an empirically justified minimal ontology for Topic Maps-based e-Learning. The proposed minimal set contains five relation types and is implemented in the TM4L Editor to support authors that experience difficulties in articulating and naming relationships.