What is abcd format for a writing piece?

There is no widely recognized format called "abcd" in writing. It's possible you are referring to a specific format used within a particular context, such as a school or organization.

If you can provide more information about where you encountered this term or what kind of writing piece you are working on, I might be able to help you understand what "abcd" format means in that context.

For example, you could tell me:

* Where did you see this term? (A specific book, website, teacher's instructions, etc.)

* What kind of writing is it for? (Essay, report, blog post, etc.)

* What is the purpose of the writing? (Inform, persuade, entertain, etc.)

With more information, I can try to identify the specific "abcd" format you are looking for and give you a better explanation.