libYAML's errors
LibYAML exposes error when parsing/emitting yaml. See https://pyyaml.org/wiki/LibYAML. More information is available directly in pyyaml's source code in their C interface. They are groupped in the following errors:

•	libyaml-parser-error
•	libyaml-emitter-error
•	libyaml-initialize-error

Conversion errors
Additional errors are thrown when converting to/from factor objects:

•	yaml-undefined-anchor
•	yaml-no-document
•	Or many errors thrown by library words (eg unparseable numbers, converting unsupported objects to yaml, etc)

Bugs
The following error probably means that there is a bug in the implementation: yaml-unexpected-event