The system text types are configured in the main schema. Only the text types that have a link="Multi" are types that are eligible to be jumped.
You can review the types by the command http://<yourservername>/gn4/edo.ashx?Cmd=help&Name=ArticleSchema.
<?xml version="1.0" encoding="utf-8"?>
<article order="Seq">
<head minOccurs="0" maxOccurs="1" link="Single" />
<webHead minOccurs="0" maxOccurs="1" link="No" />
<blogPost minOccurs="0" maxOccurs="1" link="No" />
<jumpHead minOccurs="0" maxOccurs="1" link="Multi" />
<subhead minOccurs="0" maxOccurs="1" link="Single" />
<kicker minOccurs="0" maxOccurs="1" link="Single" />
<intro minOccurs="0" maxOccurs="1" link="Single" />
<body minOccurs="0" maxOccurs="1" link="Multi" />
<webBody minOccurs="0" maxOccurs="unbounded" link="No" />
<smsBody minOccurs="0" maxOccurs="unbounded" link="No" />
<pullquote minOccurs="0" maxOccurs="unbounded" link="Single" />
<photoCaption minOccurs="0" maxOccurs="unbounded" link="Single" reference="img" />
<urlCaption minOccurs="0" maxOccurs="unbounded" link="No" reference="url" />
<audioCaption minOccurs="0" maxOccurs="unbounded" link="No" reference="audio" />
<videoCaption minOccurs="0" maxOccurs="unbounded" link="No" reference="video" />
</article>
In this example, the text types labelled jumpHead and body can have their content jumped from one extDoc (document page) to another.