The double bang !! has a special meaning in YAML. It is called “secondary tag handle” and a shorthand for !tag:yaml.org,2002: (source).6 YAML Features most programmers don’t know1.7K7Martin ThomaChairat Onyaem (Par)·Jan 8Is this applicable to Python YAML processor (e.g. PyYaml) only or any YAML processors in any languages? Looks like the latter one.