Sections: taxonomies for form fields

[stickgrinder]

Up to 2.0 version, there is no "logical" clue on different form sections other than fieldsets (imagine a multistep form with several fieldsets in each step). Form Sections would be a way to "categorize" fields to fall into one or more sections. Think them as a field-tagging system that creates orthogonal sets of fields that can be rendered with a single command.

The solution I can foresee is to create a register of tags, with associated field names, so that I could reverse-search tagged fields.
This can be approached in one or more of the following:

• Add a property to all fields-adder methods to specify a list of tags
• Add a tag() method that take an array of fieldnames
• Add a ->tag() method that add tags fluently after a field creation

Any clue?