To install multiple SVR4 packages, you will need to specify the software tag for each package as shown below.
<software type="SVR4">
<source>
<publisher>
<origin name="/net/192.168.56.2/svr4/app1.pkg"/>
</publisher>
</source>
<software_data>
<name>application1</name>
</software_data>
</software>
<software type="SVR4">
<source>
<publisher>
<origin name="/net/192.168.56.2/svr4/app2.pkg"/>
</publisher>
</source>
<software_data>
<name>application2</name>
</software_data>
</software>