In sentence "Vendors are required to fetch a single document named openapi with an extension of yml, yaml or json, inside the application module’s root META-INF folder.".
In list element "one of the allowed static files is present, i.e. META-INF/openapi.(json|yaml)".
The last should be changed to "one of the allowed static files is present, i.e. META-INF/openapi.(json|yaml|yml)" or in the first occurence the "yml" should be removed instead (but that might be a breaking change potentially).
There are two sections that define the openapi file postfix (.yaml, .yml,.json), but they are not consistent:
https://github.com/eclipse/microprofile-open-api/blob/master/spec/src/main/asciidoc/microprofile-openapi-spec.asciidoc#location-and-formats
In sentence "Vendors are required to fetch a single document named openapi with an extension of yml, yaml or json, inside the application module’s root META-INF folder.".
and
https://github.com/eclipse/microprofile-open-api/blob/master/spec/src/main/asciidoc/microprofile-openapi-spec.asciidoc#overview
In list element "one of the allowed static files is present, i.e. META-INF/openapi.(json|yaml)".
The last should be changed to "one of the allowed static files is present, i.e. META-INF/openapi.(json|yaml|yml)" or in the first occurence the "yml" should be removed instead (but that might be a breaking change potentially).