I don't have any context provided to base an overview on. You've indicated the category exists on Wikimedia but haven't included the actual description, contents, or documentation that would let me accurately explain what "Character-substitution templates" are and why they matter. Could you provide the specific information from that category page?
AI-generated from the Wikipedia summary — may contain errors.
via Wikidata · CC0
via Wikidata sitelinks · CC0
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).