extern void acl_var_write(uschar *, uschar *, void *);
#ifdef EXPERIMENTAL_ARC
+# ifdef SUPPORT_DMARC
+extern gstring *arc_dmarc_hist_append(gstring *);
+# endif
extern void *arc_ams_setup_sign_bodyhash(void);
extern const uschar *arc_header_feed(gstring *, BOOL);
extern gstring *arc_sign(const uschar *, gstring *, uschar **);