>Thank you for the explanation. I will try to find a site where this type of declaration is used and examine it.
>I still, however, don't understand how the above code/example will save me from having each application field styled in a CSS file. For example, say I want the field "customer_id" always (on all application pages) to be of 200px width. So thought I would set this width for the class "customer_id" in the CSS file. Since CSS file will be used in all pages, the set width will be applied to any Input that has class "customer_id".
>What I don't understand is how the example above will eliminate the need for this class in CSS file.

if you add

form *[name="customer_id"] {width:200px; }

to your site/application *.css, all elements such as

<form>... <input name="customer_id" ... /> ... </form>

will have a width of 200px.