Based on the spec for YAML 1.2, underscores shouldn't be allowed in numbers: https://yaml.org/spec/1.2/2009-07-21/spec.html#id2604185 However the latest `js-yaml` still allows them: package.json ``` { "dependencies": { "js-yaml": "^4.1.0" } } ``` test.js ``` const yaml = require('js-yaml'); const data = yaml.load(` string: '1_2_3' also_string: 1_2_3 `); console.log(typeof data.string); console.log(typeof data.also_string); ``` ``` $ node test.js string number ``` Is this intended behaviour? Thanks in advance.