Jacek Caban (@jacek) commented about dlls/mshtml/mshtml_private.h:
#define HTMLELEMENT_TIDS \ IHTMLDOMNode_tid, \ IHTMLDOMNode2_tid, \
- IHTMLElement_tid, \ IHTMLElement4_tid, \ IHTMLUniqueName_tid
+extern const DISPID HTMLElement_toString_dispids[];
It's just a single dispid in two places, let's keep it "duplicated" locally.