diff --git a/xml/api/crm_resource-2.22.rng b/xml/api/crm_resource-2.22.rng
index cd74da0d89..e89d850da1 100644
--- a/xml/api/crm_resource-2.22.rng
+++ b/xml/api/crm_resource-2.22.rng
@@ -1,303 +1,305 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <grammar xmlns="http://relaxng.org/ns/structure/1.0"
          datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
 
     <start>
         <ref name="element-crm-resource"/>
     </start>
 
     <define name="element-crm-resource">
         <choice>
             <ref name="agents-list" />
             <ref name="alternatives-list" />
             <ref name="constraints-list" />
             <externalRef href="generic-list-2.4.rng"/>
             <element name="metadata"> <text/> </element>
             <ref name="locate-list" />
             <ref name="operations-list" />
             <ref name="providers-list" />
             <ref name="reasons-list" />
             <ref name="resource-check" />
             <ref name="resource-config" />
             <ref name="resources-list" />
             <ref name="resource-agent-action" />
         </choice>
     </define>
 
     <define name="agents-list">
         <element name="agents">
             <attribute name="standard"> <text/> </attribute>
             <optional>
                 <attribute name="provider"> <text/> </attribute>
             </optional>
             <zeroOrMore>
                 <element name="agent"> <text/> </element>
             </zeroOrMore>
         </element>
     </define>
 
     <define name="alternatives-list">
         <element name="providers">
             <attribute name="for"> <text/> </attribute>
             <zeroOrMore>
                 <element name="provider"> <text/> </element>
             </zeroOrMore>
         </element>
     </define>
 
     <define name="constraints-list">
         <element name="constraints">
             <interleave>
                 <zeroOrMore>
                     <ref name="rsc-location" />
                 </zeroOrMore>
                 <zeroOrMore>
                     <ref name="rsc-colocation" />
                 </zeroOrMore>
             </interleave>
         </element>
     </define>
 
     <define name="locate-list">
         <element name="nodes">
             <attribute name="resource"> <text/> </attribute>
             <zeroOrMore>
                 <element name="node">
                     <optional>
                         <attribute name="state"><value>promoted</value></attribute>
                     </optional>
                     <text/>
                 </element>
             </zeroOrMore>
         </element>
     </define>
 
     <define name="rsc-location">
         <element name="rsc_location">
             <attribute name="node"> <text/> </attribute>
             <attribute name="rsc"> <text/> </attribute>
             <attribute name="id"> <text/> </attribute>
             <externalRef href="../score.rng"/>
         </element>
     </define>
 
     <define name="operations-list">
         <element name="operations">
             <oneOrMore>
                 <ref name="element-operation-list" />
             </oneOrMore>
         </element>
     </define>
 
     <define name="providers-list">
         <element name="providers">
             <attribute name="standard"> <value>ocf</value> </attribute>
             <optional>
                 <attribute name="agent"> <text/> </attribute>
             </optional>
             <zeroOrMore>
                 <element name="provider"> <text/> </element>
             </zeroOrMore>
         </element>
     </define>
 
     <define name="reasons-list">
         <choice>
             <ref name="no-resource-or-uname"/>
             <ref name="resource-and-uname"/>
             <ref name="no-resource-but-uname"/>
             <ref name="resource-but-no-uname"/>
         </choice>
     </define>
 
     <define name="no-resource-or-uname">
         <element name="reason">
             <element name="resources">
                 <zeroOrMore>
                     <element name="resource">
                         <attribute name="id"> <text/> </attribute>
                         <attribute name="running"> <data type="boolean"/> </attribute>
                         <ref name="resource-check"/>
                     </element>
                 </zeroOrMore>
             </element>
         </element>
     </define>
 
     <define name="resource-and-uname">
         <element name="reason">
-            <attribute name="running_on"> <text/> </attribute>
+            <optional>
+                <attribute name="running_on"> <text/> </attribute>
+            </optional>
             <ref name="resource-check"/>
         </element>
     </define>
 
     <define name="no-resource-but-uname">
         <element name="reason">
             <element name="resources">
                 <zeroOrMore>
                     <element name="resource">
                         <attribute name="id"> <text/> </attribute>
                         <attribute name="running"> <data type="boolean"/> </attribute>
                         <attribute name="host"> <text/> </attribute>
                         <ref name="resource-check"/>
                     </element>
                 </zeroOrMore>
             </element>
         </element>
     </define>
 
     <define name="resource-but-no-uname">
         <element name="reason">
             <attribute name="running"> <data type="boolean"/> </attribute>
             <ref name="resource-check"/>
         </element>
     </define>
 
     <define name="resource-config">
         <element name="resource_config">
             <externalRef href="resources-2.4.rng" />
             <element name="xml"> <text/> </element>
         </element>
     </define>
 
     <define name="resource-check">
         <element name="check">
             <attribute name="id"> <text/> </attribute>
             <optional>
                 <choice>
                     <attribute name="remain_stopped"><value>true</value></attribute>
                     <attribute name="promotable"><value>false</value></attribute>
                 </choice>
             </optional>
             <optional>
                 <attribute name="unmanaged"><value>true</value></attribute>
             </optional>
             <optional>
                 <attribute name="locked-to"> <text/> </attribute>
             </optional>
         </element>
     </define>
 
     <define name="resources-list">
         <element name="resources">
             <zeroOrMore>
                 <externalRef href="resources-2.4.rng" />
             </zeroOrMore>
         </element>
     </define>
 
     <define name="rsc-colocation">
         <element name="rsc_colocation">
             <attribute name="id"> <text/> </attribute>
             <attribute name="rsc"> <text/> </attribute>
             <attribute name="with-rsc"> <text/> </attribute>
             <externalRef href="../score.rng"/>
             <optional>
                 <attribute name="node-attribute"> <text/> </attribute>
             </optional>
             <optional>
                 <attribute name="rsc-role">
                     <ref name="attribute-roles"/>
                 </attribute>
             </optional>
             <optional>
                 <attribute name="with-rsc-role">
                     <ref name="attribute-roles"/>
                 </attribute>
             </optional>
         </element>
     </define>
 
     <define name="element-operation-list">
         <element name="operation">
             <optional>
                 <group>
                     <attribute name="rsc"> <text/> </attribute>
                     <attribute name="agent"> <text/> </attribute>
                 </group>
             </optional>
             <attribute name="op"> <text/> </attribute>
             <attribute name="node"> <text/> </attribute>
             <attribute name="call"> <data type="integer" /> </attribute>
             <attribute name="rc"> <data type="nonNegativeInteger" /> </attribute>
             <optional>
                 <attribute name="last-rc-change"> <text/> </attribute>
                 <attribute name="exec-time"> <data type="nonNegativeInteger" /> </attribute>
             </optional>
             <attribute name="status"> <text/> </attribute>
         </element>
     </define>
 
     <define name="resource-agent-action">
         <element name="resource-agent-action">
             <attribute name="action"> <text/> </attribute>
             <optional>
                 <attribute name="rsc"> <text/> </attribute>
             </optional>
             <attribute name="class"> <text/> </attribute>
             <attribute name="type"> <text/> </attribute>
             <optional>
                 <attribute name="provider"> <text/> </attribute>
             </optional>
             <optional>
                 <ref name="overrides-list"/>
             </optional>
             <ref name="agent-status"/>
             <optional>
                 <choice>
                     <element name="command">
                         <text />
                     </element>
                     <externalRef href="command-output-1.0.rng"/>
                 </choice>
             </optional>
         </element>
     </define>
 
     <define name="overrides-list">
         <element name="overrides">
             <zeroOrMore>
                 <element name="override">
                     <optional>
                         <attribute name="rsc"> <text/> </attribute>
                     </optional>
                     <attribute name="name"> <text/> </attribute>
                     <attribute name="value"> <text/> </attribute>
                 </element>
             </zeroOrMore>
         </element>
     </define>
 
     <define name="agent-status">
         <element name="agent-status">
             <attribute name="code"> <data type="integer" /> </attribute>
             <optional>
                 <attribute name="message"> <text/> </attribute>
             </optional>
             <optional>
                 <attribute name="execution_code"> <data type="integer" /> </attribute>
             </optional>
             <optional>
                 <attribute name="execution_message"> <text/> </attribute>
             </optional>
             <optional>
                 <attribute name="reason"> <text/> </attribute>
             </optional>
         </element>
     </define>
 
     <define name="attribute-roles">
         <choice>
             <value>Stopped</value>
             <value>Started</value>
             <value>Promoted</value>
             <value>Unpromoted</value>
 
             <!-- These synonyms for Promoted/Unpromoted are allowed for
                  backward compatibility with output from older Pacemaker
                  versions that used them -->
             <value>Master</value>
             <value>Slave</value>
         </choice>
     </define>
 </grammar>