Configurable listbox selector for special characters and custom markup?

I'd like to see a configurable list box selector for XHTML special characters and custom markup. On the configuration, you might consider an editable INI file with data in the form:

The "2x-" lines are to indicate that two occurrences of the selected character will be inserted. (Users could define a different encoding.) This is for use cases like legal writing, where the plural of one section symbol is two section symbols, ditto for paragraph symbols. A simple parsing of the INI file could display the resulting character(s) and the symbol name/custom markup in the selector.

The advantage I see of using an editable INI file is that admins could easily configure what characters and custom markup they want to have in the selector, the order it appears, etc. But you might pre-populate the INI file with all special characters and enable a commenting regime so folks can comment out characters they don't want to appear rather than deleting them. That would make it easier for admins to expand the character set later.

This would resolve an issue I have with Drupal 5.x, which is the difficulty in making a selection of special characters and custom markup handy for my site contributors.