+
+PERLVAR(Ixnv_arenaroot, XPV*) /* list of allocated xnv areas */
+PERLVAR(Ixrv_arenaroot, XPV*) /* list of allocated xrv areas */
+PERLVAR(Ixpv_arenaroot, XPV*) /* list of allocated xpv areas */
+PERLVAR(Ixpviv_arenaroot,XPVIV*) /* list of allocated xpviv areas */
+PERLVAR(Ixpvnv_arenaroot,XPVNV*) /* list of allocated xpvnv areas */
+PERLVAR(Ixpvcv_arenaroot,XPVCV*) /* list of allocated xpvcv areas */
+PERLVAR(Ixpvav_arenaroot,XPVAV*) /* list of allocated xpvav areas */
+PERLVAR(Ixpvhv_arenaroot,XPVHV*) /* list of allocated xpvhv areas */
+PERLVAR(Ixpvmg_arenaroot,XPVMG*) /* list of allocated xpvmg areas */
+PERLVAR(Ixpvlv_arenaroot,XPVLV*) /* list of allocated xpvlv areas */
+PERLVAR(Ixpvbm_arenaroot,XPVBM*) /* list of allocated xpvbm areas */
+PERLVAR(Ihe_arenaroot, XPV*) /* list of allocated he areas */
+
+ /* 5.6.0 stopped here */
+
+PERLVAR(Ipsig_pend, int *) /* per-signal "count" of pending */
+PERLVARI(Isig_pending, int,0) /* Number if highest signal pending */
+
+#ifdef USE_LOCALE_NUMERIC
+
+PERLVAR(Inumeric_radix_sv, SV *) /* The radix separator if not '.' */
+
+#endif
+
+#if defined(USE_ITHREADS)
+PERLVAR(Iregex_pad, SV**) /* All regex objects */
+PERLVAR(Iregex_padav, AV*) /* All regex objects */
+
+#ifdef USE_REENTRANT_API
+PERLVAR(Ireentrant_buffer, REENTR*) /* here we store the _r buffers */
+#endif
+
+#endif
+
+PERLVAR(Isavebegin, bool) /* save BEGINs for compiler */
+
+PERLVAR(Icustom_op_names, HV*) /* Names of user defined ops */
+PERLVAR(Icustom_op_descs, HV*) /* Descriptions of user defined ops */
+
+#ifdef PERLIO_LAYERS
+PERLVARI(Iperlio, PerlIO *,NULL)
+PERLVARI(Iknown_layers, PerlIO_list_t *,NULL)
+PERLVARI(Idef_layerlist, PerlIO_list_t *,NULL)
+#endif
+
+PERLVARI(Iencoding, SV*, Nullsv) /* character encoding */
+
+PERLVAR(Idebug_pad, struct perl_debug_pad) /* always needed because of the re extension */
+
+PERLVAR(Itaint_warn, bool) /* taint warns instead of dying */
+
+#ifdef PL_OP_SLAB_ALLOC
+PERLVAR(IOpPtr,I32 **)
+PERLVARI(IOpSpace,I32,0)
+PERLVAR(IOpSlab,I32 *)
+#endif
+
+PERLVAR(Iwantutf8, bool) /* want utf8 as the default discipline */
+
+PERLVAR(Iutf8_idstart, SV *)
+PERLVAR(Iutf8_idcont, SV *)
+
+PERLVAR(Isort_RealCmp, SVCOMPARE_t)
+
+PERLVARI(Icheckav_save, AV*, Nullav) /* save CHECK{}s when compiling */
+
+PERLVARI(Iclocktick, long, 0) /* this many times() ticks in a second */
+
+/* New variables must be added to the very end for binary compatibility.
+ * XSUB.h provides wrapper functions via perlapi.h that make this
+ * irrelevant, but not all code may be expected to #include XSUB.h. */