Clarification on <versions> sorting in Repository Metadata

The document http://maven.apache.org/ref/3.3.9/maven-repository-metadata/repository-metadata.html explains that <versions> does contain a List<Version>, hence is sorted.

When pulling real _metadata from Maven Central, e. g. http://repo.maven.apache.org/maven2/javax/ws/rs/jsr311-api/maven-metadata.xml, it is apparent that the content of <version> is _not sorted (in this example, 1.1-ea is listed after 1.1, which is a violation of the sorting, because -ea must be listed before 1.1). So effectively Maven Central devliers unsorted versions.

Also, the effectively listed XSD http://maven.apache.org/xsd/metadata-1.1.0.xsd is nonexistent, so cannot be looked but whether Maven Central is wrong, or whether actually the specification should say it must be Set<Version> instead of List<Version>.

To sum up, there should be a clarification whether <version> must be sorted according to the Maven Version Numbering Schema, whether it must be Set vs List, and whether the missing XSD should be uploaded.