Thank you for your comments! Definitely I was in stuck inventing the name for opening the new indentation. I knew that "new" was reserved for constructor but couldn't give the proper name for this method. Thanks choroba as well. He gave me hint regarding Indent::over/Indent::back pair. Those are the best.

Talking about lower case of the module name, I thought to use the module like a pragma: "use indent" to turn on new indentation and "no indent" to revert to previous indent level. I fastly recognized that there no ways for that and have left all my attempts in this direction. And the module name left without changes.

I am going to take into account all the feedbacks by holli and choroba. What is the best way -- a) update the OP with the proper remarks or b) reply with new updated post?