So you have something like <xsl:element name="foo{bar">? That's not going to be valid as an XML element Name (<foo{bar>?), so what do you want the element to be named instead in that case?

It's not an issue with XML::LibXML, which probably follows the XML spec precisely, but with XML itself. Also, as always, SSCCE - give us the shortest possible code that demonstrates the problem so we can see it.

You are correct when I'm referring to an example like:

<xsl:element name = "{foo}bar">
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In this instance, I would like that node to be left alone, unchanged. test input:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" versi
+on="1.0">
<xsl:element name="foo">
 <xsl:element name="{bar}"/>
</xsl:element>
</xsl:stylesheet>
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test output:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" versi
+on="1.0">
<foo>
 <xsl:element name="{bar}"/>
</xsl:element>
</foo>
</xsl:stylesheet>
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I'm sorry for changing the requirements.

Well, in that case perhaps add next unless $el->getAttribute('name')=~/^\w+$/; into the loop I showed, or, since that might reject valid element names, reject the unwanted names with next if $el->getAttribute('name')=~/[\{\}]/;, adding more there as necessary.

(Looking back at the original problem statement, I do have to say I'm not sure why you want to manipulate your XSL like this in the first place. XML and especially XSL is somewhat verbose in its nature...)