For each loop in xslt 1.0 - xslt

Question

How to write a for-each loop in xslt 1.0 which only consider Subbranch elements with ID=11 and 12, ignoring 13 and 14.
<root>
<branch ID='1'>
<subbranch ID='11'>
<Values DataType='String'>
<Value StringLength='3'>abc</Value>
</Values>
</subbranch>
<subbranch ID='12'>
<Values DataType='String'>
<Value StringLength='3'>def</Value>
</Values>
</subbranch>
<subbranch ID='13'>
<Values DataType='String'>
<Value StringLength='3'>uvw</Value>
</Values>
</subbranch>
<subbranch ID='14'>
<Values DataType='String'>
<Value StringLength='3'>xyz</Value>
</Values>
</subbranch>
</branch>
</root>

Answer 1

You can use xsl:for-each with an XPath expression that only matches the first two subbranches:
<xsl:template match="root">
<xsl:for-each select="branch/subbranch[#ID='11' or #ID='12']">
<!-- Emit something... -->
</xsl:for-each>
</xsl:template>
Or, alternately:
<xsl:template match="root">
<xsl:for-each select="branch/subbranch[position() < 3]">
<!-- Emit something... -->
</xsl:for-each>
</xsl:template>

Answer 2

It is recommended to avoid for-each constructions except when dealing with <xsl:key>.
You should use a match-template and apply-templates construct and just not consider the unwanted values.
This XSLT applied to your source:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output indent="yes" method="xml"/>
<xsl:template match="node() | #*">
<xsl:copy>
<xsl:apply-templates select="node() | #*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="subbranch[#ID='13']"/>
<xsl:template match="subbranch[#ID='14']"/>
</xsl:stylesheet>
gives this output:
<?xml version="1.0" encoding="UTF-8"?>
<root>
<branch ID="1">
<subbranch ID="11">
<Values DataType="String">
<Value StringLength="3">abc</Value>
</Values>
</subbranch>
<subbranch ID="12">
<Values DataType="String">
<Value StringLength="3">def</Value>
</Values>
</subbranch>
</branch>
</root>
By matching the unwanted values in empty templates you avoid those parts of the XML to get processed, e.g. <xsl:template match="subbranch[#ID='13']"/>