Example 11 does not work

[JustBlackBird]

Example 11 outputs the following error:

ERROR:

while constructing a mapping
  in "<unicode string>", line 1, column 1:
    ? - Detroit Tigers
    ^
found unacceptable key (list objects are unhashable)
  in "<unicode string>", line 1, column 3:
    ? - Detroit Tigers
      ^

[natefox]

Example 27 also throws an error

ERROR:

could not determine a constructor for the tag 'tag:clarkevans.com,2002:invoice'
  in "<unicode string>", line 1, column 5:
    --- !<tag:clarkevans.com,2002:invoice>

[PhiLhoSoft]

I don't know if that's a regression, but I got errors on examples 7, 8, 11, 23, 24, 27 and 28.
Example 25 shows an error in Json mode, but it is "normal".

FYI, the https://codebeautify.org/yaml-to-json-xml-csv parser also fails on examples 11, 24, 25 and 27.
Yaml seems hard to parse... Or they are just on a previous version of the standard. It is not indicated in the sites...

http://nodeca.github.io/js-yaml/ handles most of the cases, except multiple documents, and 24 / 27 (unknown tag), and 23 (application-specific tag).