company_note.rb

# models/company/note.rb

class Company < ApplicationRecord
  class Note < ::Note

    alias_attribute :company_id, :article_id
    alias_attribute :company, :article

    # VALIDATIONS

    COMPANY_NOTE_CATEGORIES = %w(
      History Organisation Products Technology Significance
    )
    validates :category, inclusion: { in: COMPANY_NOTE_CATEGORIES }
  end
end

game_note.rb

# models/game/note.rb
require_dependency 'note'

module Game
  class Note < ::Note

    alias_attribute :game_id, :article_id
    alias_attribute :game, :article

    # VALIDATIONS

    GAME_NOTE_CATEGORIES = %w(
      Development Publishing Technology Sound Reception
    )
    validates :category, inclusion: { in: GAME_NOTE_CATEGORIES }
  end
end

note.rb

class Note < ApplicationRecord

  # AUDIT
  audited on: [:update, :destroy]

  # RELATIONSHIPS

  belongs_to :article
  belongs_to :created_by, class_name: 'User'

  # VALIDATIONS

  VALID_NOTE_TYPES = %w(Game::Note Company::Note Person::Note)
  validates :type, presence: true, inclusion: { in: VALID_NOTE_TYPES }

  validates :category, presence: true

  validates :body, presence: true, length: { minimum: 5, maximum: 2000 }

  validates :cite_url, length: { minimum: 5, maximum: 250 }, allow_blank: true

  validates :cite_title, length: { maximum: 250 }, allow_blank: true

  validates :cite_website, length: { maximum: 100 }, allow_blank: true
end

person_note.rb

# models/person/note.rb

class Person::Note < ApplicationRecord::Note

  alias_attribute :person_id, :article_id
  alias_attribute :person, :article

  # VALIDATIONS

  PERSON_NOTE_CATEGORIES = %w(
    Personal Education Career Family Achievements
  )
  validates :category, inclusion: { in: PERSON_NOTE_CATEGORIES }
end

Terminal

Game::Note.new
(irb):3: warning: toplevel constant Note referenced by Game::Note
=> #<Note id: nil, article_id: nil, type: nil, category: nil, body: nil, cite_url: nil, cite_title: nil, cite_website: nil, created_by_id: nil, created_at: nil, updated_at: nil>
# ^^ This is a new Note class object, not a Game::Note class object