By reading the code I found out that you can validate with URL parameters, both a public feed (url=...) and raw xml data (rawdata=...), but RSS Board's docs about the tool seem to imply you can only validate the former.
Also, a bit of documentation in the README could be useful, like mentioning those parameters and maybe some other stuff like saying data must be sent via GET, etc.
By reading the code I found out that you can validate with URL parameters, both a public feed (url=...) and raw xml data (rawdata=...), but RSS Board's docs about the tool seem to imply you can only validate the former.
Also, a bit of documentation in the README could be useful, like mentioning those parameters and maybe some other stuff like saying data must be sent via GET, etc.