"Proper" YAML front-matter format?

I've been writing YAML page front-matter like this:

title: 'Using Typora with Grav'
slug: using-typora-with-grav
date: 11/25/2015
taxonomy:
topic: [web development]
tag: [opinion, grav, technique]
featherlight:
active: true

If I open that page in the Admin, it re-writes the front-matter like this:

title: 'Using Typora With Grav'
process:
markdown: true
twig: true
robots:
noindex: true
nofollow: true
slug: using-typora-with-grav
date: '25-11-2015 00:00'
taxonomy:
tag:

• opinion
• technique
• grav
  topic:
• 'web development'
  child_type: default
  featherlight:
  active: true
  TXTCopy

I assume the more verbose format is preferred?

How about some code blocks bob?

There are multiple YAML shortcuts and yes, it's a shortcut because it's often easier to write. Unfortunately the admin doesn't really know how you had something written before, it simply loads the values into the form, then after validation, it saves the results as YAML, there are rules in place that tell it to use short version up to a certain depth, and long after. I think that is past 2 levels.

I thought I had code blocks in the post via and but they didn't come out that way. Wrong syntax? Those are 3 `.

Now I'm getting code blocks I don't want!

I assume the

robots:
  noindex: true
  nofollow: true

is the default and it turns off robots, such as Google's web spider? Is so, is that the best default?