Content Subtypes module proposal (discussion)

Following text was moved from wiki page to discuss it. Use that wiki to form up a feature list and for task planning.

Inspired by Taxonomy fields module.

Often it's hard to make an “universal” set of fields to describe some real-world object with single content type. Many fields in many cases will be empty or filled in by default. The alternative is to make a lot of “pre-defined” types, but there are no useful tools to organize them and associate with a custom logic.

Another task is to add some information about the real-world object that you already have described. Additional property description needs a new field for it's representation. If you haven't predict this situation from the very start and if your site is full of content, there is a problem – a new field will be added to all existing nodes of this type, even if there is only a single node where it's value is not empty or default.

You can decide to make a “special” content type with additional field and then convert existing node to this type by copy/paste it's content or via Node Convert module.

If this situation is familiar to you, if your real-world objects have a huge variety of types or different set of properties – you'll need this module.