Name of Introductory Text Before a Section of Text

In a structured document, with sections, parts, and possibly subsections, is there a word, or prefix, or construction, to identify the introduction before a section or a subsection?

For instance, for the second subsection of section one, i.e. §1.2. one would write,

See Section 1, Subsection 2 for more details

What about the preamble/introduction of section 1?

1. Section One

This is preamble of the section 1.

1.1. Subsection 1

Text of subsection 1.1.

1.2. Subsection 2

Text of subsection 1.2.

Solution 1:

Preamble or Prerequisites may be appropriate for information that leads in to structured information but, if you are writing structured information, your information should be structured - into sections...

If you are trying to cross-reference within a technical or structured document, I would recommend giving your sections meaningful titles and cross-referencing the Sub-heading, for example:

"See: 1.2 Selecting your widget"

I would use "See:" if the link is within the document, and "Refer:" if I was directing the reader to another source, a book or WWW., etc.

If you make your headings meaningful, it will help the reader decide if they actually want or need to go there, for example:

"Introduction" - Introduction to what? Do I really need to read this??

Where as:

"Selecting the correct Widget" - Conceptual material. How do I choose my widget?

"Join widgets to sprockets" - A Task or process... How do I do it?

"Types of Widget" - Reference material. Which is the right widget for my application?