[2] YAMLストリーム (stream) は、YAML 文書を --- で区切って並べたものです。

[1] YAML Ain’t Markup Language (YAML™) revision 1.2.2, 2021-11-17T19:12:13.000Z, 2022-12-23T03:24:17.877Z https://yaml.org/spec/1.2.2/#92-streams

[3] sync — AWS CLI 2.9.9 Command Reference, 2022-12-21T18:35:29.000Z, 2022-12-23T03:25:30.344Z https://awscli.amazonaws.com/v2/documentation/api/latest/reference/s3/sync.html

[4] class YAML::Stream (Ruby 1.8.7), 2016-08-28T13:53:27.000Z, 2022-12-23T03:26:29.452Z https://docs.ruby-lang.org/ja/1.8.7/class/YAML=3a=3aStream.html

[5] PHP: yaml_parse - Manual, 2022-12-22T12:08:18.000Z, 2022-12-23T03:27:39.068Z https://www.php.net/manual/ja/function.yaml-parse.php