This blog post discusses how to create an external command for diffing files using the `git diff` tool, highlighting a lack of clear documentation on the topic. It details the necessary arguments and provides a worked example related to updating, adding, or deleting files. Additionally, the author mentions using the `oasdiff` tool for comparing OpenAPI specs and shares a basic implementation of a diff driver script that outputs human-readable changelogs. The discussion is inspired by previous blog posts and aims to clarify the process of setting up custom diff drivers.