Should I register DTO class as provider in Ionic 2

Ionic Framework ionic-v3
1

I’m new to Ionic development. Today I got struck with the problem where I have to use same DTO in a several pages and providers. Naturally I would like to create it as a separate class, but I don’t know where to put it. Which one of those pats would be the best?

  1. Register DTO as provider?

  2. Create custom file in /app folder and use as declaration?

  3. Create a custom folder in the project called /DTOs and use them in declarations?

Same question goes to all custom classes that I would like to reuse but I’m not sure if the qualify as provider…