<?xml version="1.0" encoding="UTF-8"?>
<!-- Diameter services DTD -->
-<!ELEMENT services (stack*, node*)>
+<!ELEMENT services ((stack*, node*)|(node*, stack*))>
<!ELEMENT stack EMPTY>
<!ATTLIST stack id CDATA #REQUIRED dictionary CDATA #REQUIRED validationMode (BeforeEncoding | AfterDecoding | Always | Never) #IMPLIED validationDepth (Complete | FirstError) #IMPLIED fixMode (BeforeEncoding | AfterDecoding | Always | Never) #IMPLIED ignoreFlagsOnValidation (yes | no) #IMPLIED>