1YAML::Syck and YAML.pm 0.60 breaks compatibility with older versions by
2changing the tags that are output for serialized objects.
3
4This was the old way:
5
6    --- !perl/Foo::Bar {}
7    --- !perl/@Baz []
8    --- !perl/$Quux ""
9
10New way:
11
12    --- !!perl/hash:Foo::Bar {}
13    --- !!perl/array:Baz []
14    --- !!perl/scalar:Quux ""
15
16* This change was made after discussions with the Python and Ruby
17  implementers to standardize on this form.
18* YAML::Syck was updated at the same time as YAML.pm so that they
19  serialize objects the same way.
20* YAML.pm roundtrips the new format and still parses the old (now
21  deprecated) format.
22* The best strategy is to update to the latest version.
23* There are potential problems if you use YAML for RPC and the server
24  and client versions don't match.
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26