Naming ESPHome devices with dash or underscore

ESPHome
1

I’m changing the HW completely where I run HA. Testing the new setup with a fresh install.
After I installed ESPHome (2021.11.1) on the new server I noticed it only allows lowercase, numbers and dash mark. No underscore.

In some old version where I created my nodes I have used underscore in all of the names.

Should I now rename all of my nodes with dash over the underscore?
e.g. “house_main_power” → “house-main-power”.

In the docs it is mentioned differently and underscore seems to work. But will it change in the future? Or some other potential problem that could occur?

2

Warns about underscores in hostnames to prevent DHCP/DNS problems.

  • Underscores in device names can cause strange DNS problems that are hard for users to trace, example1, example2.
  • According to RFC1912, underscores are not allowed in hostnames.
3

Seems very clear.
Underscore not to be used and to be replaced with dash.

Thanks!