The problem with using overflow: hidden in this situation is, what happens if you want to use absolute positioning to show an error message next to the form field, and it breaks out of the container. If you were using overflow: hidden, you can’t push it outside of the container.

can you explain me why did you make ol.forms float: left? I don’t understand that. I’m a rather CSS newbie but wouldn’t it be better to avoid floats and make it for example overflow: hidden?

Yes, I would treat radio buttons the same way as checkboxes, but the point of the demo is that it flexible and easy to be changed.

I definitely think maxlengths are useful if you need to restrict length, but you should still check on the server side as well. I absolutely hate tabindex though. It always ends up messing up the tab order when you start adding new fields, or adding other forms to a page. I try and avoid it.

That project sounds interesting, but I don’t think I would have the time to devote to that.

It would be nice to see how you style radio inputs. Do you treat them in the same way as your demo’d checkboxes?

I do progressive enhancement but you’ve sold me on jQuery.

Good to grab the label names as part of your error content and the CSS width assignment to inputs. What’s your thoughts on adding maxlength (That agrees with database data lengths) and tabindex (To correspond with your ordered list).

A great project for you (I think) would be to have a server process that can generate an object in JSON format that picks up all the validation rules for a table from your database.
The server-side validation would convert JSON into an object and do its validation.
At the client, jQuery could grab the same JSON string as an object for client-side validation.
Demonstrate the form with no progressions, just SEO friendly, accessible and does correct server-side sanitation and validation.
Then add the CSS to make it pretty.
Then add the jQuery to enhance the form, and validate it.
A great example of PE (progressive enhancement) and DRY (don’t repeat yourself) implimentation.

I find there are lots of good client-side behaviours that never show you what takes place on the server and how server processes have to be changed to call another process (web service), that can be shared with XHR requests.

Sorry for the long comment but I like your work as you are doing all the right things in my mind and your better placed than myself to sell the idea to the community.

Well done on your tutorials and articles.