I actually wrote a YAML parser that closed this loophole by raising an exception on YAML files that have inconsistent indents. Somebody reported exactly that as

I actually wrote a YAML parser that closed this loophole by raising an exception on YAML files that have inconsistent indents. Somebody reported exactly that as an issue on my issue tracker: https://github.com/crdoconnor/strictyaml/issues/23 https://github.com/crdoconnor/strictyaml/issues/23 I'm aware that there are a bunch of annoyances like that, but I'm still convinced the core is good and making a new standard which is stricter solves most of these issues. FWIW, I haven't run into this problem personally but it's pretty obvious that it is a problem.