How can we figure out if a package is core or not?

[Alberto Salvia Novella]

Javier Lopez:
> I use this alias:
>
> alias core.package='sh -c '\''apt-cache show "${1}" | grep -i task >/dev/null && echo yes || echo no'\'' -'
> https://github.com/chilicuil/dotfiles/blob/master/.aliases#L33
>
> Like this:
>
> $ core.package firefox
> yes
> $ core.package conky
> no

Thank you.

Since:
  - The "task" field is already at the bottom of the Terminal printing.
  - Knowing which tasks uses the package helps contributors figuring out 
if bugs affect projects where they are more involved.

I think this solution doesn't add clarity or speed in practice.