Confused about :npm, :onlyNpm, enabledManagers

[gremo]

After reading the documentation I'm a bit confused about :npm and :onlyNpm. I'll copy/paste the two presets:

:npm
Keep package.json npm dependencies updated

{
  "npm": {
    "enabled": true
  }
}

:onlyNpm
Renovate only npm dependencies

{
  "docker": {
    "enabled": false
  },
  "meteor": {
    "enabled": false
  }
}

(1) If I understand correctly, all managers are enabled by default. So what's the effect of setting :npm and why this preset exists in the first place? (2) Why :onlyNpm doesn't list other managers as well (for example, composer)? (3) Isn't that present the same as setting the following?

{
  "enabledManagers": ["npm"]
}

Really thanks for your time.

[rarkins]

Those presets are outdated / incorrect now. They were originally from early days when only npm, meteor and Docker were supported and need updating.

[gremo]

So documentation should be updated? What you suggest for enable only package.json and NPM manager?

[rarkins]

I think better to fix it or deprecate it than simply update the documentation. I recommend you use enabledManagers instead