diff --git a/pdf/plugin.jelly b/pdf/plugin.jelly
index 635a93cd..206b9e10 100644
--- a/pdf/plugin.jelly
+++ b/pdf/plugin.jelly
@@ -157,15 +157,24 @@ plugin.currentVersion           = [${plugin.currentVersion}]
       <arg value="${plugin.resources}/project2fo.xslt"/>
       <arg value="-OUT"/>
       <arg value="${internal_pdf_workingDir}/project.fo"/>
-      <arg value="-PARAM"/>
-      <arg value="basePath"/>
-      <arg value="${internal_pdf_workingDir}"/>
-      <arg value="-PARAM"/>
-      <arg value="confidential"/>
-      <arg value="${maven.pdf.confidential}"/>
+      <j:set var="_basePath" value="${internal_pdf_workingDir}"/>
+      <j:if test="${not empty(_basePath)}">
+        <arg value="-PARAM"/>
+        <arg value="basePath"/>
+        <arg value="${_basePath}"/>
+      </j:if>
+      <j:set var="_confidential" value="${maven.pdf.confidential}"/>
+      <j:if test="${not empty(_confidential)}">
+        <arg value="-PARAM"/>
+        <arg value="confidential"/>
+        <arg value="${_confidential}"/>
+      </j:if>
+      <j:set var="_paperType" value="${maven.pdf.paperType}"/>
+      <j:if test="${not empty(_paperType)}">
       <arg value="-PARAM"/>
       <arg value="paperType"/>
-      <arg value="${maven.pdf.paperType}"/>
+      <arg value="${_paperType}"/>
+      </j:if>
       <j:set var="_companyIncName" value="${maven.pdf.companyIncName}"/>
       <j:if test="${not empty(_companyIncName)}">
         <arg value="-PARAM"/>
@@ -188,9 +197,12 @@ plugin.currentVersion           = [${plugin.currentVersion}]
         <arg value="coverProjectName"/>
         <arg value="${_projectName}"/>
       </j:if>
-      <arg value="-PARAM"/>
-      <arg value="coverType"/>
-      <arg value="${maven.pdf.cover.type}"/>
+      <j:set var="_coverType" value="${maven.pdf.cover.type}"/>
+      <j:if test="${not empty(_coverType)}">
+        <arg value="-PARAM"/>
+        <arg value="coverType"/>
+        <arg value="${_coverType}"/>
+      </j:if>
       <j:set var="_coverVersion" value="${maven.pdf.cover.version}"/>
       <j:if test="${not empty(_coverVersion)}">
         <arg value="-PARAM"/>
@@ -215,21 +227,36 @@ plugin.currentVersion           = [${plugin.currentVersion}]
         <arg value="projectLogo"/>
         <arg value="${_projectLogo}"/>
       </j:if>
-      <arg value="-PARAM"/>
-      <arg value="imageDpi"/>
-      <arg value="${maven.pdf.imageDpi}"/>
-      <arg value="-PARAM"/>
-      <arg value="debug"/>
-      <arg value="${maven.pdf.debug}"/>
-      <arg value="-PARAM"/>
-      <arg value="createBookmarks"/>
-      <arg value="${maven.pdf.createBookmarks}"/>
-      <arg value="-PARAM"/>
-      <arg value="header_Height"/>
-      <arg value="${maven.pdf.cover.headerHeight}"/>
-      <arg value="-PARAM"/>
-      <arg value="footer_Height"/>
-      <arg value="${maven.pdf.cover.footerHeight}"/>
+      <j:set var="_imageDpi" value="${maven.pdf.imageDpi}"/>
+      <j:if test="${not empty(_imageDpi)}">
+        <arg value="-PARAM"/>
+        <arg value="imageDpi"/>
+        <arg value="${_imageDpi}"/>
+      </j:if>
+      <j:set var="_debug" value="${maven.pdf.debug}"/>
+      <j:if test="${not empty(_debug)}">
+        <arg value="-PARAM"/>
+        <arg value="debug"/>
+        <arg value="${_debug}"/>
+      </j:if>
+      <j:set var="_createBookmarks" value="${maven.pdf.createBookmarks}"/>
+      <j:if test="${not empty(_createBookmarks)}">
+        <arg value="-PARAM"/>
+        <arg value="createBookmarks"/>
+        <arg value="${_createBookmarks}"/>
+      </j:if>
+      <j:set var="_header_Height" value="${maven.pdf.cover.headerHeight}"/>
+      <j:if test="${not empty(_header_Height)}">
+        <arg value="-PARAM"/>
+        <arg value="header_Height"/>
+        <arg value="${_header_Height}"/>
+      </j:if>
+      <j:set var="_footer_Height" value="${maven.pdf.cover.footerHeight}"/>
+      <j:if test="${not empty(_footer_Height)}">
+        <arg value="-PARAM"/>
+        <arg value="footer_Height"/>
+        <arg value="${_footer_Height}"/>
+      </j:if>
       <sysproperty key="javax.xml.parsers.DocumentBuilderFactory" value="org.apache.xerces.jaxp.DocumentBuilderFactoryImp"/>
       <sysproperty key="javax.xml.parsers.SAXParserFactory" value="org.apache.xerces.jaxp.SAXParserFactoryImpl"/>
       <sysproperty key="java.endorsed.dirs" path="${java.home}/lib/endorsed;${maven.home}/lib/endorsed}"/>
diff --git a/pdf/src/plugin-resources/project2fo.xslt b/pdf/src/plugin-resources/project2fo.xslt
index 7730323b..5282821a 100644
--- a/pdf/src/plugin-resources/project2fo.xslt
+++ b/pdf/src/plugin-resources/project2fo.xslt
@@ -28,17 +28,17 @@
     <xsl:include href="fo-table-column-widths.xslt"/>
     <xsl:param name="basePath">.</xsl:param>
     <xsl:param name="paperType">US</xsl:param>
-    <xsl:param name="companyIncName">Apache Software Foundation, Inc.</xsl:param>
+    <xsl:param name="companyIncName"/>
     <xsl:param name="confidential">false</xsl:param>
     <xsl:param name="publicationYear"/>
     <xsl:param name="imageDpi">150</xsl:param>
     <xsl:param name="companyLogo"/>
     <xsl:param name="projectLogo"/>
-    <xsl:param name="coverProjectCompany">Apache Software Foundation</xsl:param>
-    <xsl:param name="coverProjectName">Jakarta Maven</xsl:param>
-    <xsl:param name="coverType">Project Documentation</xsl:param>
+    <xsl:param name="coverProjectCompany"/>
+    <xsl:param name="coverProjectName"/>
+    <xsl:param name="coverType"/>
     <xsl:param name="coverVersion"/>
-    <xsl:param name="coverDate">January 1, 1901</xsl:param>
+    <xsl:param name="coverDate"/>
     <xsl:param name="header_Height">0.5</xsl:param>
     <xsl:param name="footer_Height">0.3</xsl:param>
     <xsl:param name="debug">false</xsl:param>