Selected Papers from the 5th International Joint Conference on Rules and Reasoning (RuleML+RR 2021).

This document is a summary of selected papers from the 5th International Joint Conference on Rules and Reasoning (RuleML+RR 2021). The conference brought together researchers and practitioners in the field of rule technologies and reasoning. The papers included in this issue cover a range of topics, including high-utility pattern mining, rehabilitation scheduling problems, meta-reasoning over ontology, and distributed subweb specifications for traversing the web. These papers demonstrate the diversity and quality of the contributions to the conference. The document also acknowledges the reviewers and organizers who made the conference and this special issue possible. [Extracted from the article]