CRM Open Catalog Interface (OCI) - What data is sent from CRM/ISA to SRM?

Question

RE: CRM4
We have an SRM customer that is able to access our online catalog as expected, create a shopping cart and transfer it to their SRM system.  However, they're asking that we provide additional information on the item(s) and I can not determine what data is sent in the first place, let alone how to add additional information.  Specifically, they require that the UNSPSC code is included in the data...the format for which should look something like this:
NEW_ITEM-MATGROUP = 465120000
I have determined the 'how' the data is sent (via HTML if OCI_VERSION = 1) and the file that's called once the SRM customer clicks the TRANSFER button on our CRM/ISA (ocilinessend.jsp)
But, I am unable to determine the 'what' data is sent.
According to the javascript file, here's the code that is activated:
<%-- send list with oci lines --%>
<form action="<%= request.getAttribute(OciLinesSendAction.OCI_HOOK_URL)%>" method="post"
name="SUBMITFORM" target="<%=request.getAttribute(OciLinesSendAction.OCI_TARGET)%>">
<% String param = (String)request.getAttribute(OciLinesSendAction.OCI_OKCODE); %>
<% if (param != null) { %>
    <input type="hidden" name="<%=OciLinesSendAction.OCI_OKCODE%>" value="<%=param%>">
<% } %>
<% param = (String)request.getAttribute(OciLinesSendAction.OCI_CALLER); %>
<% if (param != null) { %>
    <input type="hidden" name="<%=OciLinesSendAction.OCI_CALLER%>" value="<%=param%>">
<% } %>
<% OciLineList ociLineList =
    (OciLineList)pageContext.findAttribute(OciLinesSendAction.OCI_LINE_LIST); %>
<% for (int i=0; i < ociLineList.size(); i++) { %><%=ociLineList.get(i)+"\n"%><% } %>
</form>
So, does anyone know how this works?  How does data get flagged as being relevant to be sent via an OCI Transfer?
I can not believe how limited the SAP documentation is on the CRM side of this connectivity...the SRM side has a huge amount of documentation, but none of it specifically deals with how to get a CRM connection up and running.  You'd think they'd especially want to have customers using SAP on both sides of the connection...

Answer 1

I have made some progress finally.
The items that the .jsp file sends are apparently triggered when the customer clicks on the Transfer button and the FM CRM_ISA_BASKET_GETITEMS_BBP runs.
The FM ends up pulling data from the UI Structure CRMT_ISALES_BASKETITEM_BBP which you can modify the fields sent by using transaction CRMC_MAP to add a New Entry -> UI Field, named MATGROUP with Object ORDERADM_I and one of the 42 Obj.Field's available.  I ran a test with our customer and they confirmed that the MATGROUP was now indeed being sent during the transfer.
So, now my dilemma is trying to figure out which Obj.Field already is set up for UNSPSC numbers or if there is another Object in CRM that I should look in.
In the IMG, there are SRM settings for UN/SPSC numbers, but I can not find a corresponding CRM setting.
Anyone have an idea on which Obj.Field we should use ... or perhaps one which we can map from our ERP backend to CRM that will work without having to create a new Obj.Field, which is really not what we want to have to do.