need help with xsl transformation - unwanted text - xslt

Question

I'm trying to match just the secondary-content xml tag. but it's outputting text "/ Main cotnent goes here." Why is it outputting text from the masthead and maincontent tag?
xmL:
<xml>
<system-data-structure>
<mastheads>
<masthead>
<image>
<path>/</path>
</image>
<alt/>
</masthead>
</mastheads>
<maincontent>
<content>
<p>Main content goes here. </p>
</content>
</maincontent>
<secondary-content>
<title>
<h2>Secondary Content Title</h2>
</title>
<block>
<path>/</path>
</block>
<content>
<p>Secondary main content goes here. </p>
</content>
</secondary-content>
<secondary-content>
<title></title>
<block>
<content>
<div class="aux-content-box">
<h2 class="aux-content-box">More Information</h2>
<ul>
<li>
Air Force Tuition Assistance
</li>
<li>
Army Tuition Assistance
</li>
<li>
Coast Guard Tuition Assistance
</li>
<li>
Marine Corps Tuition Assistance
</li>
<li>
Navy Tuition Assistance
</li>
<li>
National Guard State Tuition Assistance
</li>
<li>
National Guard Federal Tuition Assistance
</li>
<li>
Reserve Tuition Assistance
</li>
<li>
US Department of Veteran Affairs: Tuition Assistance Top-Up Program
</li>
</ul>
</div>
</content>
<path>/web/current-students/military/military-links-nav</path>
<name>military-links-nav</name>
</block>
<content/>
</secondary-content>
</system-data-structure>
</xml>
xsl:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" encoding="utf-8"/>
<xsl:template match="/system-data-structure">
<xsl:apply-templates select="secondary-content" />
</xsl:template>
<xsl:template match="secondary-content">
Found a learner!
</xsl:template>
</xsl:stylesheet>
output:
/ Main content goes here. Found a learner! Found a learner!

Answer 1

This is a frequently asked question. It's due to XSLT's built-in templates that implicitly drive the processing of various nodes.
Override the built-in template for text nodes with the following template:
<xsl:template match="text()"/>

Answer 2

One reason for the behaviour is with your first template matching line
<xsl:template match="/system-data-structure">
In your XML, the root element is xml, not system-data-structure. This means it doesn't match anything, and this is why the built-in templates are kicking in as described in the previous answer.
Try replacing the above line with this...
<xsl:template match="/xml/system-data-structure">
This should then yield the following output
Found a learner! Found a learner!

Answer 3

It's because in your first template, you're trying to match system-data-structure at the root level. However, xml is the root level in your XML example. Change the match to /xml/system-data-structure:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" encoding="utf-8"/>
<xsl:template match="/xml/system-data-structure">
<xsl:apply-templates select="secondary-content" />
</xsl:template>
<xsl:template match="secondary-content">
Found a learner!
</xsl:template>
</xsl:stylesheet>