This book constitutes the refereed deadline proceedings of the 28th International Conference on Graph-Based Representation and Reasoning, ICCS 2023, held in Berlin, Germany, during September 11–13, 2023.The 9 full papers, 5 short papers and 4 Posters are included in this book were carefully reviewed and selected from 32 submissions.

Complexity and Database Theory.- Functional Dependencies with Predicates: What Makes the g3-error Easy to Compute?.- Formal Concept Analysis: Theoretical Advances.- Squared symmetric formal contexts and their connections with correlation matrices.- Aggregation Functions and Extent Structure Preservation in Formal Concept Analysis.- On pseudointents in Fuzzy Formal Concept Analysis.- Maximal Ordinal Two-Factorizations.- A Note on the Number of (Maximal) Antichains in the Lattice of set Partitions.- Formal Concept Analysis: Applications.- Formal Concept Analysis for Trace Clustering in Process Mining.- Summarization of massive RDF graphs using identifier classification.- Towards a Flexible and Scalable Data Stream Algorithm in FCA.- Modelling and Explanation.- Postmodern Human-Machine Dialogues: a Pedagogical Inquiry Experiment.- Conceptual Modelling with Euler+ Diagrams.- Automatic Textual Explanations of Concept Lattices.- Semantic Web and Graphs.- Ontology Population from French Classified Ads.- Graph Extraction for Assisting Crash Simulation Data Analysis.- Posters.- Factorization of formal contexts from modal operators.- Towards confirmation measures to mixed attribute implications.- Concept lattices as a reduction tool for fuzzy relation equations.- Analysis of Slovak Court Decisions by Formal Concept Analysis and Machine Learning Methods.