Hi, according to the documentation you should be able to call `pdf.reserveobj("annot")`, but doing so results in the error "pdf.reserveobj() optional string must be "annot"". The problem is that a null pointer and not the argument is compared to "annot". According to the website, you are not ready for contributions yet, but I still attached a patch. -- Marcel Krüger --- source/texk/web2c/luatexdir/lua/lpdflib.c | 1 + 1 file changed, 1 insertion(+) diff --git a/source/texk/web2c/luatexdir/lua/lpdflib.c b/source/texk/web2c/luatexdir/lua/lpdflib.c index 7db3041..7158014 100644 --- a/source/texk/web2c/luatexdir/lua/lpdflib.c +++ b/source/texk/web2c/luatexdir/lua/lpdflib.c @@ -494,6 +494,7 @@ static int l_reserveobj(lua_State * L) case 1: if (!lua_isstring(L, -1)) luaL_error(L, "pdf.reserveobj() optional argument must be string"); + st_s = luaL_checkstring(L, 1); if (lua_key_eq(st_s, annot)) { pdf_last_annot = pdf_create_obj(static_pdf, obj_type_annot, 0); } else { -- 2.5.0