XML basics

An XML document is organized using elements. Elements are defined using tags, which usually appear in pairs. First comes the open tag, then the relevant data (or content) and then the close tag. An open tag consists of the element name surrounded by angle brackets (<>). The close tag is nearly identical with a forward slash thrown in. For example

<elementname> Element content goes here </elementname>

The ModelTools schema uses all lower case element names (but element names are case sensitive). Attributes and namespaces are not used, so this is not a complicated schema.

The content of an element may be ordinary text and/or child elements.

Empty Elements

Elements with no content and no child elements are called empty elements and are represented by a single tag that closes with a forward slash. For example

<emptyelementname/>

Comments

Comments in XML begin with <!-- and end with -->. Any text may be placed between these two markers (including angle brackets). For example

<!-- This is a comment. -->

The parsers used in ModelTools ignore all text in a file appearing before the start of the first element and after the end of the last element.