diff --git a/R/misc_v3_comp.R b/R/misc_v3_comp.R
deleted file mode 100644
index 711dd708..00000000
--- a/R/misc_v3_comp.R
+++ /dev/null
@@ -1,53 +0,0 @@
-v3_only = function(fun) {
-	setdiff(funs_v3[[fun]], funs_v4[[fun]])
-}
-
-v3_start_message = function() {
-	if (!.TMAP$v3) {
-		message("tmap v3 code detected. Specific changes listed below.")
-		.TMAP$v3 = TRUE
-	}
-	invisible(NULL)
-}
-
-v3_reset_flag = function() {
-	.TMAP$v3 = FALSE
-	invisible(NULL)
-}
-
-
-v3_instead = function(args_called, old, new, fun, extra_called = character()) {
-	args = args_called$args
-	called = args_called$called
-	
-	if (old %in% called) {
-		args[[new]] = args[[old]]
-		args[[old]] = NULL
-		
-		# may be needed to trigger something (e.g. "shape" to use symbols instead of dots)
-		if (length(extra_called)) {
-			called = unique(c(called, extra_called))
-		}
-		message(paste0(fun, " (v3->v4): use '", new, "' instead of '", old, "'"))
-	}
-	list(args = args, called = called)
-}
-
-v3_instead_value = function(args_called, old, new, fun, value_old, value_new) {
-	args = args_called$args
-	called = args_called$called
-	
-	if (old %in% called) {
-		if (identical(args[[old]], value_old)) {
-			args[[old]] = NULL
-			args[[new]] = value_new
-			if (is.null(value_old)) value_old = "NULL" 
-			message(paste0(fun, " (v3->v4): use '", new, " = ", value_new, "' instead of '", old, " = ", value_old, "'"))
-			list(args = args, called = called)
-		} else {
-			v3_instead(args_called, old, new, fun)
-		}
-	} else {
-		list(args = args, called = called)
-	}
-}
diff --git a/R/step1_rearrange.R b/R/step1_rearrange.R
index fdc94db3..e5b4914a 100644
--- a/R/step1_rearrange.R
+++ b/R/step1_rearrange.R
@@ -49,7 +49,9 @@ step1_rearrange = function(tmel) {
 	if (any(is_opt)) for (id in which(is_opt)) {
 		o2 = oth[[id]]
 		
-		if ("v3" %in% o2$calls) message("v3 code detected: as of tmap v4, the legend should be specified for each visual variable\n(e.g. with `fill.legend = tm_legend()` inside tm_polygons to control the legend of fill for polygons.", call. = FALSE)
+		cls = class(o2)[1]
+		if (substr(cls, nchar(cls)-2,nchar(cls)) == "_v3") cls = substr(cls, 1, nchar(cls) - 3)
+		if ("v3_tm_legend" %in% o2$calls) v3_tm_legend_general(fun = cls) 
 		
 		# special case: position, in case c("left", "top") is used
 		pids = grep(".position", names(o2), fixed = TRUE)
diff --git a/R/step4_helper_legends.R b/R/step4_helper_legends.R
index 508a341b..c88b91f9 100644
--- a/R/step4_helper_legends.R
+++ b/R/step4_helper_legends.R
@@ -44,11 +44,21 @@ step4_plot_collect_legends = function(tmx) {
 				
 				legs2 = lapply(legs, function(legs_aes) {
 					legs_aes$vneutral = unlist(lapply(legs_aes$legend, function(l) l$vneutral), use.names = FALSE, recursive = FALSE)
+					if ("icon_scale" %in% names(legs_aes$legend[[1]])) {
+						legs_aes$icon_scale = legs_aes$legend[[1]]$icon_scale
+					} else {
+						legs_aes$icon_scale = 1
+					}
 					legs_aes
 				})
 				
 				# find shared legends
 				
+				icon_scales = vapply(legs2, function(l) {
+					as.numeric(l$icon_scale)
+				}, FUN.VALUE = numeric(1))
+				icon_scale = if (any(icon_scales != 1)) icon_scales[which(icon_scales != 1)[1]] else 1
+				
 				clones = vapply(legs2, function(l) {
 					a = l$legend[[1]]$aes
 					if (!is.null(a)) a else ""
@@ -120,9 +130,10 @@ step4_plot_collect_legends = function(tmx) {
 								
 							}
 							
-							
 							leleg = legs_aes$legend[[k]]
 							
+			
+							
 							# get gp values from shared legends (slave)
 							if ("clones" %in% names(leleg)) {
 								clist = leleg$clones
@@ -132,6 +143,11 @@ step4_plot_collect_legends = function(tmx) {
 								}
 							}
 							
+							# in case the size legend consists of symbols shapes that represented icons
+							if (icon_scale > 1 && legnm == "size") {
+								gp$size = gp$size * icon_scale
+							}
+							
 							leleg$gp = gp
 							leleg$vneutral = NULL
 							leleg$vvalues = NULL
diff --git a/R/tm_add_legend.R b/R/tm_add_legend.R
index 52dcbd8f..551c2d19 100644
--- a/R/tm_add_legend.R
+++ b/R/tm_add_legend.R
@@ -35,6 +35,17 @@ tm_add_legend = function(...,
 	#args = lapply(as.list(match.call()[-1]), eval, envir = parent.frame())
 	if (missing(labels)) stop("tm_add_legend: labels required", call. = FALSE)
 	args = c(as.list(environment()), list(...))
+	if (type %in% c("fill", "symbol", "line")) {
+		v3_add_legend(type, names(args))
+		if ("col" %in% names(args) && !c("fill" %in% names(args))) {
+			args$fill = args$col
+			args$col = NULL
+		}
+		if ("border.col" %in% names(args)) {
+			args$col = args$border.col
+			args$border.col = NULL
+		}
+	}
 	tm_element_list(do.call(tm_element, c(args, list(subclass = c("tm_add_legend", "tm_component")))))
 }
 
diff --git a/R/tm_element.R b/R/tm_element.R
index dfbd9064..a5442869 100644
--- a/R/tm_element.R
+++ b/R/tm_element.R
@@ -32,7 +32,7 @@ tm_element_list_sel = function(tml, subclass) {
 	if (inherits(e2, "tm_legend")) {
 		names(e2) = paste0("legend.", names(e2))
 		
-		e2 = tm_element_list(do.call(tm_element, c(e2, list(calls = "v3", subclass = "tm_options"))))
+		e2 = tm_element_list(do.call(tm_element, c(e2, list(calls = "v3_tm_legend", subclass = c("tm_legend_v3", "tm_options")))))
 	}
 	structure(c(e1, e2), class = "tmap")
 }
diff --git a/R/tm_layers_polygons.R b/R/tm_layers_polygons.R
index 12bc67b2..bd518f00 100644
--- a/R/tm_layers_polygons.R
+++ b/R/tm_layers_polygons.R
@@ -128,6 +128,13 @@ tm_polygons = function(fill = tm_const(),
 	args_called = as.list(match.call()[-1]) #lapply(as.list(match.call()[-1]), eval, envir = parent.frame())
 	
 	if (any(v3_only("tm_polygons") %in% names(args))) {
+		
+		layer_fun = paste0("tm", {if ("called_from" %in% names(args)) {
+			args$called_from
+		} else {
+			"polygons"
+		}})
+		
 		v3_start_message()
 		if (!("style" %in% names(args))) {
 			if (!"breaks" %in% names(args)) {
@@ -139,29 +146,27 @@ tm_polygons = function(fill = tm_const(),
 			style = args$style
 		}
 		
-		imp = function(name, value) {
-			if (name %in% names(args)) args[[name]] else value
-		}
-		
-		fill.scale.args = list(n = imp("n", 5), 
+
+		fill.scale.args = list(n = v3_impute(args, "n", 5), 
 							   style = style, 
-							   style.args = imp("style.args", list()), 
-							   breaks = imp("breaks", NULL), 
-							   interval.closure = imp("interval.closure", "left"), 
-							   drop.levels = imp("drop.levels", FALSE),
-							   midpoint = imp("midpoint", NULL), 
-							   as.count = imp("as.count", NA), 
-							   values = imp("palette", NA), 
-							   values.repeat = !imp("stretch.palette", TRUE), 
-							   values.range = imp("contrast", NA), 
+							   style.args = v3_impute(args, "style.args", list()), 
+							   breaks = v3_impute(args, "breaks", NULL), 
+							   interval.closure = v3_impute(args, "interval.closure", "left"), 
+							   drop.levels = v3_impute(args, "drop.levels", FALSE),
+							   midpoint = v3_impute(args, "midpoint", NULL), 
+							   as.count = v3_impute(args, "as.count", NA), 
+							   values = v3_impute(args, "palette", NA, "values"), 
+							   values.repeat = !v3_impute(args, "stretch.palette", TRUE, "values.repeat"), 
+							   values.range = v3_impute(args, "contrast", NA, "values.range"), 
 							   values.scale = 1, 
-							   value.na = imp("colorNA", NA), 
-							   value.null = imp("colorNULL", NA), 
+							   value.na = v3_impute(args, "colorNA", NA, "value.na"), 
+							   value.null = v3_impute(args, "colorNULL", NA, "value.null"), 
 							   value.neutral = NA, 
-							   labels = imp("labels", NULL), 
-							   label.na = imp("textNA", NA), 
+							   labels = v3_impute(args, "labels", NULL), 
+							   label.na = v3_impute(args, "textNA", "Missing", "label.na"), 
 							   label.null = NA, 
-							   label.format = imp("legend.format", list()))
+							   label.format = v3_impute(args, "legend.format", list(), "label.format"))
+			
 		fill.scale.args$fun_pref = if (style == "cat") {
 			"categorical"
 		} else if (style %in% c("fixed", "sd", "equal", "pretty", "quantile", "kmeans", "hclust", "bclust", "fisher", "jenks", "dpih", "headtails", "log10_pretty")) {
@@ -176,6 +181,8 @@ tm_polygons = function(fill = tm_const(),
 			stop("unknown style")
 		}
 		
+		if ("style" %in% names(args)) v3_tm_scale_instead_of_style(style, scale_fun = fill.scale.args$fun_pref, vv = "fill", layer_fun = layer_fun, arg_list = v3_list_get())
+		
 		fill.scale = do.call("tm_scale", args = fill.scale.args)		
 		
 		if ("convert2density" %in% names(args) && args$convert2density) {
@@ -197,17 +204,19 @@ tm_polygons = function(fill = tm_const(),
 			fill_alpha = args$alpha
 		}
 		
-		fill.legend.args = alist(title = imp("title", NA),
-								 show = imp("legend.show", NULL),
-								 na.show = imp("na.show", NA),
-								 format = imp("legend.format", list()),
-								 orientation = ifelse(imp("legend.is.portrait", TRUE), "portrait", "landscape"),
-								 reverse = imp("legend.reverse", FALSE))
+		fill.legend.args = list(title = v3_impute(args, "title", NA),
+								 show = v3_impute(args, "legend.show", NULL),
+								 na.show = v3_impute(args, "na.show", NA),
+								 format = v3_impute(args, "legend.format", list()),
+								 orientation = ifelse(v3_impute(args, "legend.is.portrait", TRUE), "portrait", "landscape"),
+								 reverse = v3_impute(args, "legend.reverse", FALSE))
 		
 		fill.legend = do.call("tm_legend", fill.legend.args)
 		
 		if ("legend.hist" %in% names(args) && args$legend.hist) {
 			fill.chart = tm_chart_histogram()
+			v3_tm_chart_hist(layer_fun = layer_fun, vv = "fill", arg = "legend.hist")
+			
 			# to do: histogram title
 		}
 		
diff --git a/R/tm_layers_symbols.R b/R/tm_layers_symbols.R
index 051a7b9f..e36d1eae 100644
--- a/R/tm_layers_symbols.R
+++ b/R/tm_layers_symbols.R
@@ -167,6 +167,7 @@ tm_symbols = function(size = tm_const(),
 	if (!is.null(res)) {
 		fill = res$fill
 		col = res$col
+		col_alpha = res$col_alpha
 		fill_alpha = res$fill_alpha
 		fill.scale = res$fill.scale
 		fill.legend = res$fill.legend
@@ -176,7 +177,6 @@ tm_symbols = function(size = tm_const(),
 		shape.legend = res$shape.legend
 		fill.chart = res$fill.chart
 	}
-	
 
 	tm_element_list(tm_element(
 		layer = "symbols",
@@ -263,6 +263,12 @@ v3_symbols = function(args, args_called) {
 	v3 = v3_only("tm_symbols")
 	
 	if (any(v3 %in% names(args))) {
+		layer_fun = paste0("tm_", {if ("called_from" %in% names(args)) {
+			args$called_from
+		} else {
+			"symbols"
+		}})
+		
 		v3_start_message()
 		if (!("style" %in% names(args))) {
 			if (!"breaks" %in% names(args)) {
@@ -274,30 +280,27 @@ v3_symbols = function(args, args_called) {
 			style = args$style
 		}
 		
-		imp = function(name, value) {
-			if (name %in% names(args)) args[[name]] else value
-		}
-		
+		v3_list_init()
 		# v3 visual variable: fill
-		fill.scale.args = list(n = imp("n", 5), 
+		fill.scale.args = list(n = v3_impute(args, "n", 5), 
 							   style = style, 
-							   style.args = imp("style.args", list()), 
-							   breaks = imp("breaks", NULL), 
-							   interval.closure = imp("interval.closure", "left"), 
-							   drop.levels = imp("drop.levels", FALSE),
-							   midpoint = imp("midpoint", NULL), 
-							   as.count = imp("as.count", NA), 
-							   values = imp("palette", NA), 
-							   values.repeat = !imp("stretch.palette", TRUE), 
-							   values.range = imp("contrast", NA), 
+							   style.args = v3_impute(args, "style.args", list()), 
+							   breaks = v3_impute(args, "breaks", NULL), 
+							   interval.closure = v3_impute(args, "interval.closure", "left"), 
+							   drop.levels = v3_impute(args, "drop.levels", FALSE),
+							   midpoint = v3_impute(args, "midpoint", NULL), 
+							   as.count = v3_impute(args, "as.count", NA), 
+							   values = v3_impute(args, "palette", NA, "values"), 
+							   values.repeat = !v3_impute(args, "stretch.palette", TRUE, "values.repeat"), 
+							   values.range = v3_impute(args, "contrast", NA, "values.range"), 
 							   values.scale = 1, 
-							   value.na = imp("colorNA", NA), 
-							   value.null = imp("colorNULL", NA), 
+							   value.na = v3_impute(args, "colorNA", NA, "value.na"), 
+							   value.null = v3_impute(args, "colorNULL", NA, "value.null"), 
 							   value.neutral = NA, 
-							   labels = imp("labels", NULL), 
-							   label.na = imp("textNA", NA), 
+							   labels = v3_impute(args, "labels", NULL), 
+							   label.na = v3_impute(args, "textNA", NA, "label.na"), 
 							   label.null = NA, 
-							   label.format = imp("legend.format", list()))
+							   label.format = v3_impute(args, "legend.format", list(), "label.format"))
 		fill.scale.args$fun_pref = if (style == "cat") {
 			"categorical"
 		} else if (style %in% c("fixed", "sd", "equal", "pretty", "quantile",
@@ -314,61 +317,81 @@ v3_symbols = function(args, args_called) {
 			stop("unknown style")
 		}
 		
-		if ("style" %in% names(args)) {
-			message("tm_symbols (v3->v4): instead of 'style = \"", style, "\"', pleaase use 'fill.scale = tm_scale_", fill.scale.args$fun_pref, "()'")
-		}
-		
-		
+		if ("style" %in% names(args)) v3_tm_scale_instead_of_style(style, scale_fun = fill.scale.args$fun_pref, vv = "fill", layer_fun = layer_fun, arg_list = v3_list_get())
 		fill.scale = do.call("tm_scale", args = fill.scale.args)		
 		
 		if ("col" %in% names(args_called)) {
 			fill = args_called$col
+			isn_fill = is.null(fill)
+			v3_message_col_fill(layer_fun = layer_fun)
+			if (isn_fill) {
+				v3_message_vv_null(layer_fun = layer_fun)
+				fill = NA
+			}
 			col = tm_const()
 		} else {
 			fill = tm_const()
 			col = tm_const()
+			isn_fill = FALSE
 		}
+		
 		if ("border.col" %in% names(args)) {
 			col = args$border.col
+			isn_col = is.null(col)
+			if (!("col" %in% names(args_called))) v3_message_col_fill(layer_fun = layer_fun)
+			if (isn_col) {
+				if (!isn_fill) v3_message_vv_null(layer_fun = layer_fun)
+				col = NA
+			}
 		}
 		
 		
 		if ("alpha" %in% names(args)) {
+			v3_message_fill_alpha(layer_fun = layer_fun)
 			fill_alpha = args$alpha
 		} else {
 			fill_alpha = tm_const()
 		}
 		
-		fill.legend.args = alist(title = imp("title.col", NA),
-								 show = imp("legend.show", NULL),
-								 na.show = imp("na.show", NA),
-								 format = imp("legend.format", list()),
-								 orientation = ifelse(imp("legend.is.portrait", TRUE), "portrait", "landscape"),
-								 reverse = imp("legend.reverse", FALSE))
+		if ("border.alpha" %in% names(args)) {
+			v3_message_col_alpha(layer_fun = layer_fun)
+			col_alpha = args$border.alpha
+		} else {
+			col_alpha = tm_const()
+		}
 		
+		v3_list_init()
+		fill.legend.args = list(title = v3_impute(args, "title.col", NA, "title"),
+								 show = v3_impute(args, "legend.show", NULL, "show"),
+								 na.show = v3_impute(args, "na.show", NA),
+								 format = v3_impute(args, "legend.format", list(), "format"),
+								 orientation = ifelse(v3_impute(args, "legend.is.portrait", TRUE, "orientation"), "portrait", "landscape"),
+								 reverse = v3_impute(args, "legend.reverse", FALSE, "reverse"))
 		fill.legend = do.call("tm_legend", fill.legend.args)
+		v3_tm_legend(fun = layer_fun, vv = "col", arg_list = v3_list_get())
 		
 		
 		# v3 visual variable: size
-		size.scale.args = list(ticks = imp("sizes.legend", NULL),
+		v3_list_init()
+		size.scale.args = list(ticks = v3_impute(args, "sizes.legend", NULL, "ticks"),
 							   value.range = {if ("size.lim" %in% names(args)) {
 							   	c(args[["size.lim"]][1] / args[["size.lim"]][2], 1)
 							   }},
-							   limits = imp("size.lim", NULL),
+							   limits = v3_impute(args, "size.lim", NULL, "limits"),
 							   outliers.trunc = c(TRUE, FALSE),
-							   labels = imp("sizes.legend.labels", NULL),
+							   labels = v3_impute(args, "sizes.legend.labels", NULL, "labels"),
 							   fun_pref = "continuous")
-		
+		if ("size" %in% names(args_called)) v3_tm_scale(scale_fun = "continuous", vv = "size", layer_fun = layer_fun, arg_list = v3_list_get())
 		size.scale = do.call("tm_scale", args = size.scale.args)		
 		
-		
-		size.legend.args = alist(title = imp("title.size", NA),
-								 show = imp("legend.size.show", NULL),
-								 na.show = imp("showNA", NA),
-								 format = imp("legend.format", list()),
-								 orientation = ifelse(imp("legend.size.is.portrait", FALSE), "portrait", "landscape"),
-								 reverse = imp("legend.size.reverse", FALSE))
-		
+		v3_list_init()
+		size.legend.args = list(title = v3_impute(args, "title.size", NA, "title"),
+								 show = v3_impute(args, "legend.size.show", NULL),
+								 na.show = v3_impute(args, "showNA", NA),
+								 format = v3_impute(args, "legend.format", list(), "format"),
+								 orientation = ifelse(v3_impute(args, "legend.size.is.portrait", FALSE), "portrait", "landscape"),
+								 reverse = v3_impute(args, "legend.size.reverse", FALSE))
+		if ("size" %in% names(args_called)) v3_tm_legend(fun = layer_fun, vv = "size", arg_list = v3_list_get())
 		size.legend = do.call("tm_legend", size.legend.args)
 		
 		# v3 visual variable: shape
@@ -382,35 +405,45 @@ v3_symbols = function(args, args_called) {
 			shapes.style = args$shapes.style
 		}
 		
-		shape.scale.args = list(n = imp("shapes.n", 5), 
+		v3_list_init()
+		shape.scale.args = list(n = v3_impute(args, "shapes.n", 5, "n"), 
 								style = shapes.style, 
-								style.args = imp("shapes.style.args", list()), 
-								breaks = imp("shapes.breaks", NULL), 
-								interval.closure = imp("shapes.interval.closure", "left"), 
-								drop.levels = imp("drop.levels", FALSE),
-								midpoint = imp("midpoint", NULL), 
-								as.count = imp("as.count", NA), 
-								values = imp("shapes", 21:25),
-								labels = imp("shapes.labels", NULL), 
-								label.na = imp("shape.textNA", NA), 
+								style.args = v3_impute(args, "shapes.style.args", list(), "style.args"), 
+								breaks = v3_impute(args, "shapes.breaks", NULL, "breaks"), 
+								interval.closure = v3_impute(args, "shapes.interval.closure", "left", "interval.closure"), 
+								drop.levels = v3_impute(args, "drop.levels", FALSE),
+								midpoint = v3_impute(args, "midpoint", NULL), 
+								as.count = v3_impute(args, "as.count", NA), 
+								value.neutral = v3_impute(args, "shapes.legend", NA, "value.neutral"),
+								values = v3_impute(args, "shapes", 21:25, "values"),
+								labels = v3_impute(args, "shapes.labels", NULL, "labels"), 
+								label.na = v3_impute(args, "shape.textNA", NA, "label.na"), 
 								label.null = NA, 
-								label.format = imp("legend.format", list()),
+								label.format = v3_impute(args, "legend.format", list(), "label.format"),
 								fun_pref = "intervals")
-		
 		shape.scale = do.call("tm_scale", args = shape.scale.args)		
+		if ("shape" %in% names(args_called)) {
+			if ("shapes.style" %in% names(args)) {
+				v3_tm_scale_instead_of_style(shapes.style, scale_fun = shape.scale.args$fun_pref, vv = "shape", layer_fun = layer_fun, arg_list = v3_list_get())
+			} else {
+				v3_tm_scale(scale_fun = shape.scale.args$fun_pref, vv = "shape", layer_fun = layer_fun, arg_list = v3_list_get())
+			}
+		}
 		
-		
-		shape.legend.args = alist(title = imp("title.shape", NA),
-								 show = imp("legend.shape.show", NULL),
-								 na.show = imp("shape.showNA ", NA),
-								 format = imp("legend.format", list()),
-								 orientation = ifelse(imp("legend.shape.is.portrait", TRUE), "portrait", "landscape"),
-								 reverse = imp("legend.shape.reverse", FALSE))
-		
+		v3_list_init()
+		shape.legend.args = list(title = v3_impute(args, "title.shape", NA),
+								 show = v3_impute(args, "legend.shape.show", NULL),
+								 na.show = v3_impute(args, "shape.showNA ", NA),
+								 format = v3_impute(args, "legend.format", list(), "format"),
+								 orientation = ifelse(v3_impute(args, "legend.shape.is.portrait", TRUE), "portrait", "landscape"),
+								 reverse = v3_impute(args, "legend.shape.reverse", FALSE))
+		if ("shape" %in% names(args_called))v3_tm_legend(fun = layer_fun, vv = "shape", arg_list = v3_list_get())
 		shape.legend = do.call("tm_legend", shape.legend.args)
 		
 		if ("legend.hist" %in% names(args) && args$legend.hist) {
 			fill.chart = tm_chart_histogram()
+			v3_tm_chart_hist(layer_fun = layer_fun, vv = "fill", arg = "legend.hist")
+			
 			# to do: histogram title
 		} else {
 			fill.chart = tm_chart_none()
@@ -418,6 +451,7 @@ v3_symbols = function(args, args_called) {
 		
 		list(fill = fill,
 			 col = col,
+			 col_alpha = col_alpha,
 			 fill_alpha = fill_alpha,
 			 fill.scale = fill.scale,
 			 fill.legend = fill.legend,
@@ -464,6 +498,8 @@ tm_dots = function(fill = tm_const(),
 				   ...) {
 	
 		args = c(as.list(environment()), list(...))
+		args$called_from = "dots"
+		
 		tm = do.call(tm_symbols, args)
 		tm[[1]]$layer = c("dots", "symbols")
 		tm
@@ -511,6 +547,8 @@ tm_bubbles = function(size = tm_const(),
 					  ...) {
 	
 	args = c(as.list(environment()), list(...))
+	args$called_from = "bubbles"
+	
 	tm = do.call(tm_symbols, args)
 	tm[[1]]$layer = c("bubbles", "symbols")
 	tm
@@ -556,6 +594,7 @@ tm_squares = function(size = tm_const(),
 					  ...) {
 	
 	args = c(as.list(environment()), list(...))
+	args$called_from = "squares"
 	tm = do.call(tm_symbols, args)
 	tm[[1]]$layer = c("squares", "symbols")
 	tm
diff --git a/R/tm_layers_text.R b/R/tm_layers_text.R
index 51eb82ab..5c46f3ee 100644
--- a/R/tm_layers_text.R
+++ b/R/tm_layers_text.R
@@ -238,24 +238,9 @@ tm_text = function(text = tm_const(),
 	#if (FALSE) {
 	args = list(...)
 	
-	# dput(names(formals("tm_text")))
-	v3 = c("root", "clustering", "size.lim", "sizes.legend", 
-		   "sizes.legend.labels", "sizes.legend.text", "n", "style", "style.args", 
-		   "as.count", "breaks", "interval.closure", "palette", "labels", 
-		   "drop.levels", "labels.text", "midpoint", "stretch.palette", 
-		   "contrast", "colorNA", "textNA", "showNA", "colorNULL", "fontface", 
-		   "fontfamily", "alpha", "case", "bg.alpha", 
-		   "size.lowerbound", "print.tiny", "scale", "auto.placement", 
-		   "along.lines", "overwrite.lines", "xmod", "ymod", "title.size", 
-		   "title.col", "legend.size.show", "legend.col.show", "legend.format", 
-		   "legend.size.is.portrait", "legend.col.is.portrait", "legend.size.reverse", 
-		   "legend.col.reverse", "legend.hist", "legend.hist.title", "legend.size.z", 
-		   "legend.col.z", "legend.hist.z", "id", "auto.palette.mapping", "shadow",
-		   "max.categories")
-	
-	
-	if (any(v3 %in% names(args))) {
-		message("tm_text: Deprecated tmap v3 code detected. Code translated to v4")
+
+	if (any(v3_only("tm_text") %in% names(args))) {
+		v3_start_message()
 		if (!("style" %in% names(args))) {
 			if (!"breaks" %in% names(args)) {
 				style = "pretty"
@@ -266,29 +251,26 @@ tm_text = function(text = tm_const(),
 			style = args$style
 		}
 		
-		imp = function(name, value) {
-			if (name %in% names(args)) args[[name]] else value
-		}
-		
-		col.scale.args = list(n = imp("n", 5), 
+		v3_list_init()
+		col.scale.args = list(n = v3_impute(args, "n", 5), 
 				   style = style, 
-				   style.args = imp("style.args", list()), 
-				   breaks = imp("breaks", NULL), 
-				   interval.closure = imp("interval.closure", "left"), 
-				   drop.levels = imp("drop.levels", FALSE),
-				   midpoint = imp("midpoint", NULL), 
-				   as.count = imp("as.count", NA), 
-				   values = imp("palette", NA), 
-				   values.repeat = !imp("stretch.palette", TRUE), 
-				   values.range = imp("contrast", NA), 
+				   style.args = v3_impute(args, "style.args", list()), 
+				   breaks = v3_impute(args, "breaks", NULL), 
+				   interval.closure = v3_impute(args, "interval.closure", "left"), 
+				   drop.levels = v3_impute(args, "drop.levels", FALSE),
+				   midpoint = v3_impute(args, "midpoint", NULL), 
+				   as.count = v3_impute(args, "as.count", NA), 
+				   values = v3_impute(args, "palette", NA, "values"), 
+				   values.repeat = !v3_impute(args, "stretch.palette", TRUE, "values.repeat"), 
+				   values.range = v3_impute(args, "contrast", NA, "values.range"), 
 				   values.scale = 1, 
-				   value.na = imp("colorNA", NA), 
-				   value.null = imp("colorNULL", NA), 
+				   value.na = v3_impute(args, "colorNA", NA, "value.na"), 
+				   value.null = v3_impute(args, "colorNULL", NA, "value.null"), 
 				   value.neutral = NA, 
-				   labels = imp("labels", NULL), 
-				   label.na = imp("textNA", "Missing"), 
+				   labels = v3_impute(args, "labels", NULL), 
+				   label.na = v3_impute(args, "textNA", "Missing", "label.na"), 
 				   label.null = NA, 
-				   label.format = imp("legend.format", list()))
+				   label.format = v3_impute(args, "legend.format", list(), "label.format"))
 		col.scale.args$fun_pref = if (style == "cat") {
 			"categorical"
 		} else if (style %in% c("fixed", "sd", "equal", "pretty", "quantile", "kmeans", "hclust", "bclust", "fisher", "jenks", "dpih", "headtails", "log10_pretty")) {
@@ -301,39 +283,61 @@ tm_text = function(text = tm_const(),
 			stop("unknown style")
 		}
 		
-		col.scale = do.call("tm_scale", args = col.scale.args)		
+		if ("style" %in% names(args)) v3_tm_scale_instead_of_style(style, scale_fun = col.scale.args$fun_pref, vv = "col", layer_fun = "tm_text", arg_list = v3_list_get())
 		
-		col.legend.args = list(title = imp("title.col", NA),
-								show = imp("legend.col.show", NULL),
-								na.show = imp("na.show", NA),
-								format = imp("legend.format", list()),
-								orientation = ifelse(imp("legend.col.is.portrait", TRUE), "portrait", "landscape"),
-								reverse = imp("legend.col.reverse", FALSE))
+		col.scale = do.call("tm_scale", args = col.scale.args)		
 		
+		v3_list_init()
+		col.legend.args = list(title = v3_impute(args, "title.col", NA, "title"),
+								show = v3_impute(args, "legend.col.show", NULL, "show"),
+								na.show = v3_impute(args, "na.show", NA),
+								format = v3_impute(args, "legend.format", list(), "format"),
+								orientation = ifelse(v3_impute(args, "legend.col.is.portrait", TRUE, "orientation"), "portrait", "landscape"),
+								reverse = v3_impute(args, "legend.col.reverse", FALSE, "reverse"))
+
+		v3_tm_legend(fun = "tm_text", vv = "col", arg_list = v3_list_get())
 		col.legend = do.call("tm_legend", col.legend.args)
 		
-		text.scale = tm_scale_asis(value.neutral = imp("sizes.legend.text", NA))
+		v3_list_init()
+		text.scale = tm_scale_asis(value.neutral = v3_impute(args, "sizes.legend.text", NA, "value.neutral"))
+		v3_tm_scale(scale_fun = "asis", vv = "text", layer_fun = "tm_text", arg_list = v3_list_get())
 		
-		size.scale.args = list(values = tmap_seq(0, 1, power = 1/imp("root", 3)),
-							   limits = imp("size.lim", NULL),
-							   outliers.trunc = c(imp("print.tiny", FALSE), TRUE),
-							   ticks = imp("breaks", NULL),
-							   midpoint = imp("midpoint", NULL),
-							   labels = imp("sizes.legend.labels", NULL))
-		size.scale = do.call("tm_scale_continuous", size.scale.args)
-		
-		size.legend.args = list(title = imp("title.size", NA),
-							   show = imp("legend.size.show", NULL),
-							   na.show = imp("na.show", NA),
-							   format = imp("legend.format", list()),
-							   orientation = ifelse(imp("legend.size.is.portrait", TRUE), "portrait", "landscape"),
-							   reverse = imp("legend.size.reverse", FALSE))
-							   
 		if ("legend.hist" %in% names(args) && args$legend.hist) {
 			col.chart = tm_chart_histogram()
+			v3_tm_chart_hist(layer_fun = "tm_text", vv = "col", arg = "legend.hist")
 			# to do: histogram title
-		}				   
+		}	
+		
+		v3_list_init()
+		size.scale.args = list(values = tmap_seq(0, 1, power = 1/v3_impute(args, "root", 3, "values = tmap_seq(0, 1, power = 1/<root>)")),
+							   values.scale = v3_impute(args, "scale", 1, "values.scale"),
+							   limits = v3_impute(args, "size.lim", NULL),
+							   outliers.trunc = c(v3_impute(args, "print.tiny", FALSE), TRUE),
+							   ticks = v3_impute(args, "breaks", NULL),
+							   midpoint = v3_impute(args, "midpoint", NULL),
+							   labels = v3_impute(args, "sizes.legend.labels", NULL))
+		v3_tm_scale(scale_fun = "continuous", vv = "size", layer_fun = "tm_text", arg_list = v3_list_get())
+		size.scale = do.call("tm_scale_continuous", size.scale.args)
+		
+		
+		v3_list_init()
+		size.legend.args = list(title = v3_impute(args, "title.size", NA, "title"),
+							   show = v3_impute(args, "legend.size.show", NULL, "show"),
+							   na.show = v3_impute(args, "na.show", NA),
+							   format = v3_impute(args, "legend.format", list(), "format"),
+							   orientation = ifelse(v3_impute(args, "legend.size.is.portrait", TRUE, "orientation"), "portrait", "landscape"),
+							   reverse = v3_impute(args, "legend.size.reverse", FALSE, "reverse"))
+		v3_tm_legend(fun = "tm_text", vv = "size", arg_list = v3_list_get())
+		size.legend = do.call("tm_legend", size.legend.args)
+		
+			   
 
+		v4_opt_args = c("along.lines", "shadow", "just", "clustering", "point.label", "remove.overlap")
+		v3_opt_args = c("along.lines", "shadow", "just", "clustering", "auto.placement", "remove.overlap")
+		
+		#if ()
+			
+		
 	#}
 	}
 	
diff --git a/R/tm_shape.R b/R/tm_shape.R
index b4af1b53..7742a33c 100644
--- a/R/tm_shape.R
+++ b/R/tm_shape.R
@@ -43,7 +43,7 @@ tm_shape = function(shp,
 	args = as.list(match.call(expand.dots = TRUE)[-1])
 
 	if ("projection" %in% names(args)) {
-		warning("The 'projection' argument of 'tm_shape()' is deprecated as of tmap 4.0. Pleaes use 'crs' instead.", call. = FALSE)
+		v3_instead_message(arg_old = "projection", arg_new = "crs", fun = "tm_shape")
 		crs = args$projection
 	}
 	
diff --git a/R/tmapGridSymbols.R b/R/tmapGridSymbols.R
index f66ec3b7..100cbb2a 100644
--- a/R/tmapGridSymbols.R
+++ b/R/tmapGridSymbols.R
@@ -72,15 +72,16 @@ tmapGridSymbols = function(shpTM, dt, gp, bbx, facet_row, facet_col, facet_page,
 				
 
 				if (!is.na(shi) && shi>999) {
+					size = gp$size[i]*2/3 * args$icon.scale
 					grbs <- if (gp$lwd[i] == 0) {
 						gList(shapeLib[[shi-999]])	
 					} else {
 						gList(shapeLib[[shi-999]], rectGrob(gp=gpar(fill=NA, col=gp$col[i], lwd=gp$lwd[i])))	
 					}
-					gTree(children=grbs, vp=viewport(x=grid::unit(coords[i,1] + justx * gp$size[i]*2/3, "native"), 
-													 y=grid::unit(coords[i,2] + justy * gp$size[i]*2/3, "native"),
-													 width=unit(gp$size[i]*2/3, "lines"),
-													 height=unit(gp$size[i]*2/3, "lines")))
+					gTree(children=grbs, vp=viewport(x=grid::unit(coords[i,1] + justx * size, "native"), 
+													 y=grid::unit(coords[i,2] + justy * size, "native"),
+													 width=unit(size, "lines"),
+													 height=unit(size, "lines")))
 				} else {
 					pointsGrob(x=grid::unit(coords[i,1] + justx * gp$size[i], "native"), 
 							   y=grid::unit(coords[i,2] + justx * gp$size[i], "native"),
diff --git a/R/tmapLeaflet_layers.R b/R/tmapLeaflet_layers.R
index ac0fbf76..fe1f3fa6 100644
--- a/R/tmapLeaflet_layers.R
+++ b/R/tmapLeaflet_layers.R
@@ -96,6 +96,7 @@ tmapLeafletLines = function(shpTM, dt, pdt, popup.format, hdt, idt, gp, bbx, fac
 }
 
 tmapLeafletSymbols = function(shpTM, dt, pdt, popup.format, hdt, idt, gp, bbx, facet_row, facet_col, facet_page, id, pane, group, o, ...) {
+	args = list(...)
 	lf = get_lf(facet_row, facet_col, facet_page)
 	
 	rc_text = frc(facet_row, facet_col)
@@ -148,6 +149,8 @@ tmapLeafletSymbols = function(shpTM, dt, pdt, popup.format, hdt, idt, gp, bbx, f
 			symbols_icons <- merge_icons(iconLib)
 			size = gp2$width[sid] / gp2$baseSize
 			
+			size[sid] = size[sid] * args$icon.scale
+			
 			for (i in seq_along(sid)) {
 				symbols$iconUrl[sid[i]] = symbols_icons$iconUrl[i]
 				symbols$iconWidth[sid[i]] <- symbols_icons$iconWidth[i] * size[i]
diff --git a/R/tmapScaleCategorical.R b/R/tmapScaleCategorical.R
index 39c7aaa3..66904e03 100644
--- a/R/tmapScaleCategorical.R
+++ b/R/tmapScaleCategorical.R
@@ -172,12 +172,16 @@ tmapScaleCategorical = function(x1, scale, legend, chart, o, aes, layer, layer_a
 		}
 		attr(labs, "align") = label.format$text.align
 		
+		# special case: if icons are used, specify this information in the symbol legend, such that it can be taken (in step4_plot_collect_legends) by other legends (e.g. for symbol sizes)
+		icon_scale = if ((aes == "shape") && any(values > 999)) layer_args$icon.scale else 1
+		
 		legend = within(legend, {
 			nitems = length(labs)
 			labels = labs
 			dvalues = vals
 			vvalues = values
 			vneutral = value.neutral
+			icon_scale = icon_scale
 			na.show = get("na.show", envir = parent.env(environment()))
 			scale = "categorical"
 		})
diff --git a/R/tmapScaleIntervals.R b/R/tmapScaleIntervals.R
index 39f2bf3e..ce2093c9 100644
--- a/R/tmapScaleIntervals.R
+++ b/R/tmapScaleIntervals.R
@@ -92,7 +92,7 @@ tmapScaleIntervals = function(x1, scale, legend, chart, o, aes, layer, layer_arg
 			rng <- range(x1, na.rm = TRUE)
 			if (rng[1] < 0 && rng[2] > 0 && is.null(midpoint)) {
 				
-				if (show.messages) message("Variable(s) \"", paste(aes, collapse = "\", \""), "\" contains positive and negative values, so midpoint is set to 0. Set midpoint = NA to show the full spectrum of the color palette.")
+				if (show.messages) message(paste0("[scale] tm_", layer[1], ":() the data variable assigned to '", aes, "' contains positive and negative values, so midpoint is set to 0. Set 'midpoint = NA' in 'fill.scale = tm_scale_intervals(<HERE>)' to use all visual values (e.g. colors)"))
 				midpoint <- 0
 			} else {
 				if ((n %% 2) == 1) {
@@ -136,7 +136,7 @@ tmapScaleIntervals = function(x1, scale, legend, chart, o, aes, layer, layer_arg
 	
 		# detransform log 
 		if (is.log) {
-			if (any((breaks %% 1) != 0)) warning("non-rounded breaks occur, because style = \"log10_pretty\" is designed for large values", call. = FALSE)
+			if (any((breaks %% 1) != 0)) message("non-rounded breaks occur, because style = \"log10_pretty\" is designed for large values")
 			breaks <- 10^breaks
 		}
 		
diff --git a/R/tmapScale_misc.R b/R/tmapScale_misc.R
index c4b8e7f3..1c36680b 100644
--- a/R/tmapScale_misc.R
+++ b/R/tmapScale_misc.R
@@ -39,13 +39,10 @@ get_scale_defaults = function(scale, o, aes, layer, cls, ct = NULL) {
 		value.blank = getAesOption("value.blank", o, aes, layer, cls = cls)
 		if (is.na(value.na) || identical(value.na, value.blank)) label.na = ""
 		
-		
-		
 		# label.na TRUE: always show NA's, but use option
 		# label.na FALSE or "": never show NA's
 		# label.na NA: show NA is there are any
 		# label.na "qwerty" always snow NA's
-		
 		label.show = !isFALSE(label.na) && (isTRUE(label.na) || (!is.na(label.na) && label.na != ""))
 		if (is.na(label.na)) label.show = NA # will be TRUE if there are NAs
 		if (is.logical(label.na)) label.na = getAesOption("label.na", o, aes, layer, cls = cls)
diff --git a/R/tmap_options.R b/R/tmap_options.R
index 1baef313..85c9b000 100644
--- a/R/tmap_options.R
+++ b/R/tmap_options.R
@@ -1187,8 +1187,10 @@ tm_format = function(format, ...) {
 	}
 	formatArgs$style = NA
 	
+	
+	
 	if ("title" %in% names(formatArgs)) {
-		warning("The 'title' argument of 'tm_format()' is deprecated as of tmap 4.0. Please use 'tm_title()' instead.", call. = FALSE)
+		v3_use_component("title", "tm_title", "tm_format")
 		title = formatArgs$title
 		formatArgs$title = NULL
 		do.call(tm_options, formatArgs) + tm_title(text = title)
diff --git a/R/v4_v3.R b/R/v4_v3.R
new file mode 100644
index 00000000..47ff09c4
--- /dev/null
+++ b/R/v4_v3.R
@@ -0,0 +1,168 @@
+v3_only = function(fun) {
+	setdiff(funs_v3[[fun]], funs_v4[[fun]])
+}
+
+v3_start_message = function() {
+	if (!.TMAP$v3) {
+		message("-- tmap v3 code detected --")
+		.TMAP$v3 = TRUE
+	}
+	invisible(NULL)
+}
+
+v3_reset_flag = function() {
+	.TMAP$v3 = FALSE
+	invisible(NULL)
+}
+
+
+v3_use_component = function(arg = "title", comp = "tm_title", container = "tm_format") {
+	v3_start_message()
+	message(paste0("[v3->v4] ", container, "(): use ", comp, "() instead of the argument '", arg, "'"))
+}
+
+v3_tm_scale_instead_of_style = function(style, scale_fun, vv, layer_fun, arg_list) {
+	if (scale_fun == "intervals") {
+		arg_list$old = c("style", arg_list$old)
+		arg_list$new = c("style", arg_list$new)
+	}
+	if (length(arg_list$old)) {
+		al = do.call(paste, c(mapply(function(x,y) {
+			if (x == y) paste0("'", x, "'") else paste0("'", x, "' (rename to '", y, "')")
+		}, arg_list$old, arg_list$new, SIMPLIFY = FALSE), sep = ", "))
+		xtra = paste0(" and migrate the argument(s) ", al, " to 'tm_scale_", scale_fun, "(<HERE>)'")
+	} else {
+		xtra = ""
+	}
+	
+	message(paste0("[v3->v4] ", layer_fun, "(): instead of 'style = \"", style, "\"', use '", vv, ".scale = tm_scale_", scale_fun, "()'", xtra))
+}
+
+v3_instead_message = function(arg_old, arg_new, fun) {
+	v3_start_message()
+	message(paste0("[v3->v4] ", fun, "(): use '", arg_new, "' instead of '", arg_old, "'"))
+}
+
+
+v3_instead = function(args_called, old, new, fun, extra_called = character()) {
+	args = args_called$args
+	called = args_called$called
+	
+	if (old %in% called) {
+		args[[new]] = args[[old]]
+		args[[old]] = NULL
+		
+		# may be needed to trigger something (e.g. "shape" to use symbols instead of dots)
+		if (length(extra_called)) {
+			called = unique(c(called, extra_called))
+		}
+		message(paste0("[v3->v4] ", fun, "(): use '", new, "' instead of '", old, "'"))
+	}
+	list(args = args, called = called)
+}
+
+v3_instead_value = function(args_called, old, new, fun, value_old, value_new) {
+	args = args_called$args
+	called = args_called$called
+	
+	if (old %in% called) {
+		if (identical(args[[old]], value_old)) {
+			args[[old]] = NULL
+			args[[new]] = value_new
+			if (is.null(value_old)) value_old = "NULL" 
+			message(paste0("[v3->v4] ", fun, "(): use '", new, " = ", value_new, "' instead of '", old, " = ", value_old, "'"))
+			list(args = args, called = called)
+		} else {
+			v3_instead(args_called, old, new, fun)
+		}
+	} else {
+		list(args = args, called = called)
+	}
+}
+
+v3_list_init = function() {
+	.TMAP$v3_list = list(old = character(), new = character())
+	#.TMAP$v3_list = paste0(.TMAP$v3_list, v3_list_impute_item(name, value)
+	invisible(NULL)	
+}
+v3_list_impute_item = function(name, new_name) {
+	.TMAP$v3_list$old = c(.TMAP$v3_list$old, name)
+	.TMAP$v3_list$new = c(.TMAP$v3_list$new, new_name)
+}
+v3_list_get = function() {
+	.TMAP$v3_list
+}
+
+v3_impute = function(args, name, value, new_name = name) {
+	if (name %in% names(args)) {
+		v3_list_impute_item(name, new_name)
+		args[[name]]
+	} else value
+}
+
+v3_list_text = function(olds, news) {
+	do.call(paste, c(mapply(function(x,y) {
+		if (x == y) {
+			paste0("'", x, "'")
+		} else if (nchar(y) < 20) {
+			paste0("'", x, "' (rename to '", y, "')")
+		} else {
+			paste0("'", x, "' (use '", y, "')")
+		}
+	}, olds , news, SIMPLIFY = FALSE), sep = ", "))	
+}
+
+v3_tm_legend = function(fun, vv, arg_list) {
+	if (length(arg_list$old)) {
+		al = v3_list_text(olds = arg_list$old, news = arg_list$new)
+		message(paste0("[v3->v4] ", fun, "(): migrate the argument(s) related to the legend of the visual variable '", vv, "', namely ", al, " to '", vv, ".legend = tm_legend(<HERE>)'"))
+	}
+	NULL
+}
+
+v3_tm_legend_general = function(fun) {
+	v3_start_message()
+	message(paste0("[v3->v4] ", fun, "(): use 'tm_legend()' inside a layer function, e.g. 'tm_polygons(..., fill.legend = tm_legend())'"))
+}
+
+
+v3_tm_scale = function(scale_fun, vv, layer_fun, arg_list) {
+	if (length(arg_list$old)) {
+		al = v3_list_text(olds = arg_list$old, news = arg_list$new)
+		message(paste0("[v3->v4] ", layer_fun, "(): migrate the argument(s) related to the scale of the visual variable '", vv, "', namely ", al, " to '", vv, ".scale = tm_scale_", scale_fun, "(<HERE>)'"))
+	}
+	NULL
+}
+
+v3_tm_chart_hist = function(layer_fun, vv, arg) {
+	message(paste0("[v3->v4] ", layer_fun, "(): use '", vv, ".chart = tm_chart_histogram()' instead of '", arg, " = TRUE'"))
+	
+}
+
+v3_message_col_fill = function(layer_fun = layer_fun) {
+	message(paste0("[v3->v4] ", layer_fun, "(): use 'fill' for the fill color of polygons/symbols (instead of 'col'), and 'col' for the outlines (instead of 'border.col')"))
+}
+
+v3_message_vv_null = function(layer_fun = layer_fun) {
+	message(paste0("[v3->v4] ", layer_fun, "(): use 'NA' instead of 'NULL' to hide a visual variable"))
+}
+
+
+v3_message_fill_alpha = function(layer_fun = layer_fun) {
+	message(paste0("[v3->v4] ", layer_fun, "(): use 'fill_alpha' instead of 'alpha''"))
+}
+
+v3_message_col_alpha = function(layer_fun = layer_fun) {
+	message(paste0("[v3->v4] ", layer_fun, "(): use 'col_alpha' instead of 'border.alpha''"))
+}
+
+v3_add_legend = function(type, args) {
+	newtype = c(fill = "polygons", symbol = "symbols", line = "lines")	
+	message(paste0("[v3->v4] tm_add_legend(): use 'type = \"", newtype[type],"\"' instead of 'type = \"", type,"\"'"))
+	if ("col" %in% args && !c("fill" %in% args)) {
+		message(paste0("[v3->v4] tm_add_legend(): use 'fill' instead of 'coll' for the fill color of ", newtype[type]))
+	}
+	if ("border.col" %in% args) {
+		message(paste0("[v3->v4] tm_add_legend(): use 'col' instead of 'border.col' for the outline color of ", newtype[type]))
+	}
+}