private void addCommonRefAttributes(XmlAttributes attr, Reference ref) {
		attr.addAttribute("ADDRESS", XmlProgramUtilities.toString(ref.getFromAddress()));
		int opIndex = ref.getOperandIndex();
		if (opIndex != CodeUnit.MNEMONIC) {
			attr.addAttribute("OPERAND_INDEX", opIndex, true);
		}
		attr.addAttribute("USER_DEFINED", ref.getSource() == SourceType.USER_DEFINED);
	}
@param element
@param language
@param overwrite
Ghidra/Features/Base/src/main/java/ghidra/app/util/xml/MarkupXmlMgr.java