The first letter of each word in a tag being applied to APIs needs to be capitalized, keeping the tags being applied across APIs the same look and feel for organizing and publishing to documentation
OpenAPI Tags Upper Case Error
Message: Tag Names MUST Have First Letter in Each Word Capitalized
Policies
OpenAPI Tags
Tags at the OpenAPI level organize your API into logical groups. They need names, descriptions, and consistent casing to actually serve their purpose in documentation and discovery.