After you have created an HTML input form, you will need to create an FDML document. FDML stands for "Forms Definition Markup Language" and can be thought of as a language, understood only by NetForms, similar to the HTML document description language. It, too, consists of "tags" that are delimited by less-than (<) and greater-than (>) characters. FDML documents contain tags that instruct NetForms how to format the data entered by an author in the input form as well as how to act on the data once it is formatted.

There are three types of NetForms tags:

• Primary Directives
• Supplemental Directives
• Insertion Commands

In the sections below, we'll introduce you to each type of command and give you examples to get you started.