We use a linter called HTMLHint for our “Analyze HTML” feature. So that tool is what gives us the errors you might see when using that feature:

There is a particular rule in HTMLHint named space-tab-mixed-disabled, the purpose of which is to warn you when you are using inconsistent indentation. Like you are allowed to use spaces, or tabs, but not both, which is a good practice for clean code. We had that misconfigured where it wanted only spaces, so if you preferred tabs and set up your editor to use tabs (completely fine, of course), the Analyze HTML feature would bark at you about that. Now if you use tabs, and do so consistently, Analyze HTML will be chill about it.