Relaxed property binding rules have the following changes:

1. Kebab-case format (lower-case, hyphen-separated) must be used for prefixes. Examples of this are demo and demo-config.
2. Property names can use kebab-case, camel-case, or snake-case. Examples of this are user-Name, firstName, and telephone_number.
3. The upper case underscore format that is usually used for environment variables should be followed, where the underscore should only be used to separate parts of the key. The upper case underscore format is usually used for environment variables. The underscore is used to separate parts of the key. An example of this would be DEMO_ENV_1.

The complete set of rules for relaxed bindings can be seen in the Spring Boot documentation at https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html#boot-features-external-config-relaxed-binding.