Yes, but objects, refs, tags came all in 1.2. StrictYAML got rid of all these, as all the safer YAML variants. E.g. perl5 still uses 1.0 for its cpan metadata

Yes, but objects, refs, tags came all in 1.2. StrictYAML got rid of all these, as all the safer YAML variants. E.g. perl5 still uses 1.0 for its cpan metadata abstraction, and still has to restrict these. I maintain the https://metacpan.org/pod/YAML::Safe https://metacpan.org/pod/YAML::Safe module, which allows whitelisting of certain objects.