Where do I store classes and ids that the user inputs in my custom module? I am creating a module that I would like to submit to the drupal.org repository. In the admin section of the module there are various input fields where the user is able to enter classes and ids for various elements that appear on specific nodes. It's basically a module that enables the user to do theming that would otherwise require custom code.

Since I'm not a Drupal rock-star in any way, and I have only worked in custom code and website specific modules, I have a very important question:

How do I store the classes/ids that the module's user will submit?

I guess that there are 3 options here:


Store the classes/ids in a module-specific table in the database
Store the classes/ids in the "Variable" table of the database
Store the classes/ids in a file, in the module's directory


I have some pros/cons in mind about each case (e.g. I don't like the idea that a theming element would be stored in the database) but I would like your input too: which one of the methods above is the best and drupal-friendly? If I missed an option, please feel free to list it.
Of your three options, 2 would be a huge burden to a site in performance, and 3 will likely be a security issue. So I'd go with 1.

For reference, see the Block Class module.