The TXmlEngTextNode class inherits from TXmlEngCharacterData and represents the textual content (termed "character data" in XML) of an Element or TXmlEngAttr.
If there is no markup inside an element's content, the text is contained in a single TXmlEngTextNode that is the only child of the element. If there is markup, it is parsed into the information items (elements, comments, etc.) and the TXmlEngTextNode nodes that form the list of children of the element.
When a document is first made available via the DOM, there is only one TXmlEngTextNode node for each block of text. Users may create adjacent TXmlEngTextNode nodes that represent the contents of a given element without any intervening markup, but should be aware that there is no way to represent the separations between these nodes in XML or HTML, so they will not (in general) persist between DOM editing sessions.
No lexical check is done on the content of a TXmlEngTextNode node and depending on its position in the document, some characters must be escaped during serialization using character references. For example, the characters "<&" if the textual content is part of an element or an attribute, the character sequence "]]>" when part of an element, the quotation mark character " or the apostrophe character ' when part of an attribute.
http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/core.html#ID-1312295772