+=item sv_vcatpvfn(sv, pat, patlen, args, svargs, svmax, used_locale)
+
+Processes its arguments like C<vsprintf> and appends the formatted output
+to an SV. Uses an array of SVs if the C style variable argument list is
+missing (NULL). Indicates if locale information has been used for formatting.
+
+ void sv_catpvfn _((SV* sv, const char* pat, STRLEN patlen,
+ va_list *args, SV **svargs, I32 svmax,
+ bool *used_locale));
+
+=item sv_vsetpvfn(sv, pat, patlen, args, svargs, svmax, used_locale)
+
+Works like C<vcatpvfn> but copies the text into the SV instead of
+appending it.
+
+ void sv_setpvfn _((SV* sv, const char* pat, STRLEN patlen,
+ va_list *args, SV **svargs, I32 svmax,
+ bool *used_locale));
+
+=item SvUV
+
+Returns the unsigned integer which is in the SV.
+
+ UV SvUV(SV* sv)
+
+=item SvUVX
+
+Returns the unsigned integer which is stored in the SV.
+
+ UV SvUVX(SV* sv)
+