Maybe four..
<participating-org role="Funding" type="40">DfID</participating-org>
DfID
DFID
Department for International Development
UK Government Department for Int Dev
etc...
uniquely
identifies
<participating-org role="Funding" type="40" ref="GB-1">DfID</participating-org>
ref="GB-1"
"GB-1"
<iati-identifer>GB-1-204095</iati-identifier>
"204095"
uniquely
identifies
"GB-1"
"GB-1-204095"
<transaction ref="20120014">
<transaction-type code="IF"/>
<provider-org>DfID</provider-org>
<value value-date="2015-06-15">1000</value>
<transaction-date iso-date="2015-06-15" />
</transaction>
<transaction ref="20120014">
<transaction-type code="IF"/>
<provider-org ref="GB-1">DfID</provider-org>
<value value-date="2015-06-15">1000</value>
<transaction-date iso-date="2015-06-15" />
</transaction>
ref="GB-1"
DfID
DFID
Department for International Development
UK Government Department for Int Dev
etc...
uniquely
identifies
"GB-1"
<transaction ref="20120014">
<transaction-type code="IF"/>
<provider-org ref="GB-1" provider-activity-id="GB-1-204095">DfID</provider-org>
<value value-date="2015-06-15">1000</value>
<transaction-date iso-date="2015-06-15" />
</transaction>
<transaction ref="20120014">
<transaction-type code="IF"/>
<provider-org ref="GB-1">DfID</provider-org>
<value value-date="2015-06-15">1000</value>
<transaction-date iso-date="2015-06-15" />
</transaction>
provider-activity-id="GB-1-204095"
uniquely
identifies
"GB-1-204095"
ref="GB-1"
"GB-1-204095"
<provider-org ref="GB-1" provider-activity-id="GB-1-204095">DfID</provider-org>
"GB-1"
"GB-1-202545"
"ABC-123"
"ABC"
<participating-org>
<transaction>
using the standard to link:
"GB-1"
"GB-1-202545"
"ABC-123"
"ABC"
<participating-org>
<transaction>
"XYZ-123"
"XYZ"
<participating-org>
<transaction>
multi-level....