There is no built in Control Policy that can limit the Copy Request button functionality that I am aware of. However you could comment out the copy button so it will not show when viewing previous requests.
To do so you need to edit the requestprofile.xsl file here: “CA\ Service Catalog\view\webapps\usm\explorer\request”
Search for “cloneclick()”
Comment the button out
<!--
<xsl:if test="not($mode) and not($fmode) and ($canAdd) and string-length(/xmlRoot/icguinode/icguinodeinfo[21])>0">
<td class="pagesection">
<xsl:call-template name="page_button">
<xsl:with-param name="id" select="'clone'" />
<xsl:with-param name="text" select="$xslcontent/clone" />
<xsl:with-param name="titletext" select="$xslcontent/clone_tooltip" />
<xsl:with-param name="onclick">cloneclick()</xsl:with-param>
</xsl:call-template>
</td>
</xsl:if>
-->
Save
Delete the translet files here “CA\ Service Catalog\view\translets”, and then recycle the catalog service. The copy button should no longer display on previous requests.
Hope this helps!