Optional Levels

[kylecannon]

Here is my problem.

I have a 1999 Ford F-250 Super Duty with a 6.8L V10

My schema levels are: make, model, year, engine

We sell alternators so depending on what option they selected from the factory for the alternator can mean that they can have either a 6 or 8 groove serpentine system. However on other vehicles such as a 2002 Toyota Camry 2.4L I6 the pulley is standard.

What I would like to see is when you can have optional levels in the schema that are hidden until that particular instance of selecting that vehicle may require additional information. By default, this level can be null or blank for when it's not required. When all the regular fields that are standard are filled out, the optional field can display if more information is needed.