it is prefixed with "opt"; it should be so prefixed until these
versions are obsolete.]
- "hidden-service-dir" NL
+ "hidden-service-dir" *(SP VersionNum) NL
[At most once.]
- Present only if this router stores and serves v2 hidden service
- descriptors.
+ Present only if this router stores and serves hidden service
+ descriptors. If any VersionNum(s) are specified, this router
+ supports those descriptor versions. If none are specified, it
+ defaults to version 2 descriptors.
2.2. Extra-info documents