diff --git a/cmd/tools/vast/vast.v b/cmd/tools/vast/vast.v
index 50deb639d9..5c48d7e3a1 100644
--- a/cmd/tools/vast/vast.v
+++ b/cmd/tools/vast/vast.v
@@ -444,9 +444,9 @@ fn (t Tree) stmt(node ast.Stmt) &Node {
 fn (t Tree) import_module(node ast.Import) &Node {
 	mut obj := new_object()
 	obj.add_terse('ast_type', t.string_node('Import'))
-	obj.add('mod', t.string_node(node.mod))
-	obj.add('alias', t.string_node(node.alias))
-	obj.add('syms', t.array_node_import_symbol(node.syms))
+	obj.add_terse('mod', t.string_node(node.mod))
+	obj.add_terse('alias', t.string_node(node.alias))
+	obj.add_terse('syms', t.array_node_import_symbol(node.syms))
 	obj.add('comments', t.array_node_comment(node.comments))
 	obj.add('next_comments', t.array_node_comment(node.next_comments))
 	obj.add('pos', t.position(node.pos))
@@ -458,7 +458,7 @@ fn (t Tree) import_module(node ast.Import) &Node {
 
 fn (t Tree) import_symbol(node ast.ImportSymbol) &Node {
 	mut obj := new_object()
-	obj.add('name', t.string_node(node.name))
+	obj.add_terse('name', t.string_node(node.name))
 	obj.add('pos', t.position(node.pos))
 	return obj
 }
@@ -485,9 +485,10 @@ fn (t Tree) comment(node ast.Comment) &Node {
 fn (t Tree) const_decl(node ast.ConstDecl) &Node {
 	mut obj := new_object()
 	obj.add_terse('ast_type', t.string_node('ConstDecl'))
-	obj.add('is_pub', t.bool_node(node.is_pub))
-	obj.add('is_block', t.bool_node(node.is_block))
-	obj.add('fields', t.array_node_const_field(node.fields))
+	obj.add_terse('is_pub', t.bool_node(node.is_pub))
+	obj.add_terse('is_block', t.bool_node(node.is_block))
+	obj.add_terse('fields', t.array_node_const_field(node.fields))
+	obj.add_terse('attrs', t.array_node_attr(node.attrs))
 	obj.add('end_comments', t.array_node_comment(node.end_comments))
 	obj.add('pos', t.position(node.pos))
 	return obj
@@ -496,11 +497,12 @@ fn (t Tree) const_decl(node ast.ConstDecl) &Node {
 fn (t Tree) const_field(node ast.ConstField) &Node {
 	mut obj := new_object()
 	obj.add_terse('ast_type', t.string_node('ConstField'))
-	obj.add('mod', t.string_node(node.mod))
-	obj.add('name', t.string_node(node.name))
-	obj.add('expr', t.expr(node.expr))
-	obj.add('is_pub', t.bool_node(node.is_pub))
-	obj.add('typ', t.type_node(node.typ))
+	obj.add_terse('mod', t.string_node(node.mod))
+	obj.add_terse('name', t.string_node(node.name))
+	obj.add_terse('expr', t.expr(node.expr))
+	obj.add_terse('is_pub', t.bool_node(node.is_pub))
+	obj.add_terse('is_markused', t.bool_node(node.is_markused))
+	obj.add_terse('typ', t.type_node(node.typ))
 	obj.add('comments', t.array_node_comment(node.comments))
 	obj.add('comptime_expr_value', t.comptime_expr_value(node.comptime_expr_value))
 	obj.add('pos', t.position(node.pos))
@@ -527,18 +529,18 @@ fn (t Tree) fn_decl(node ast.FnDecl) &Node {
 	obj.add_terse('ast_type', t.string_node('FnDecl'))
 	obj.add_terse('name', t.string_node(node.name))
 	obj.add_terse('mod', t.string_node(node.mod))
-	obj.add('is_deprecated', t.bool_node(node.is_deprecated))
-	obj.add('is_pub', t.bool_node(node.is_pub))
-	obj.add('is_variadic', t.bool_node(node.is_variadic))
+	obj.add_terse('is_deprecated', t.bool_node(node.is_deprecated))
+	obj.add_terse('is_pub', t.bool_node(node.is_pub))
+	obj.add_terse('is_variadic', t.bool_node(node.is_variadic))
 	obj.add('is_anon', t.bool_node(node.is_anon))
-	obj.add('is_noreturn', t.bool_node(node.is_noreturn))
-	obj.add('is_manualfree', t.bool_node(node.is_manualfree))
+	obj.add_terse('is_noreturn', t.bool_node(node.is_noreturn))
+	obj.add_terse('is_manualfree', t.bool_node(node.is_manualfree))
 	obj.add('is_main', t.bool_node(node.is_main))
 	obj.add('is_test', t.bool_node(node.is_test))
 	obj.add('is_conditional', t.bool_node(node.is_conditional))
-	obj.add('is_exported', t.bool_node(node.is_exported))
+	obj.add_terse('is_exported', t.bool_node(node.is_exported))
 	obj.add('is_keep_alive', t.bool_node(node.is_keep_alive))
-	obj.add('is_unsafe', t.bool_node(node.is_unsafe))
+	obj.add_terse('is_unsafe', t.bool_node(node.is_unsafe))
 	obj.add_terse('receiver', t.struct_field(node.receiver))
 	obj.add('receiver_pos', t.position(node.receiver_pos))
 	obj.add_terse('is_method', t.bool_node(node.is_method))
@@ -597,8 +599,8 @@ fn (t Tree) struct_decl(node ast.StructDecl) &Node {
 	obj.add_terse('is_union', t.bool_node(node.is_union))
 	obj.add('pos', t.position(node.pos))
 	obj.add_terse('fields', t.array_node_struct_field(node.fields))
-	obj.add('generic_types', t.array_node_type(node.generic_types))
-	obj.add('attrs', t.array_node_attr(node.attrs))
+	obj.add_terse('generic_types', t.array_node_type(node.generic_types))
+	obj.add_terse('attrs', t.array_node_attr(node.attrs))
 	obj.add('end_comments', t.array_node_comment(node.end_comments))
 	obj.add_terse('embeds', t.array_node_embed(node.embeds))
 	return obj
@@ -746,6 +748,7 @@ fn (t Tree) global_field(node ast.GlobalField) &Node {
 	obj.add_terse('expr', t.expr(node.expr))
 	obj.add_terse('typ', t.type_node(node.typ))
 	obj.add_terse('has_expr', t.bool_node(node.has_expr))
+	obj.add_terse('is_markused', t.bool_node(node.is_markused))
 	obj.add('comments', t.array_node_comment(node.comments))
 	obj.add('pos', t.position(node.pos))
 	obj.add('typ_pos', t.position(node.typ_pos))
diff --git a/vlib/builtin/builtin.v b/vlib/builtin/builtin.v
index 5194ff9ece..3b5d807425 100644
--- a/vlib/builtin/builtin.v
+++ b/vlib/builtin/builtin.v
@@ -128,7 +128,7 @@ pub:
 	kind    AttributeKind
 }
 
-[used]
+[markused]
 fn v_segmentation_fault_handler(signal int) {
 	eprintln('signal 11: segmentation fault')
 	print_backtrace()
diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index df5df3851e..eeeadfc4b9 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -288,11 +288,12 @@ pub mut:
 // const field in const declaration group
 pub struct ConstField {
 pub:
-	mod    string
-	name   string
-	expr   Expr // the value expr of field; everything after `=`
-	is_pub bool
-	pos    token.Position
+	mod         string
+	name        string
+	expr        Expr // the value expr of field; everything after `=`
+	is_pub      bool
+	is_markused bool // an explict `[markused]` tag; the const will NOT be removed by `-skip-unused`, no matter what
+	pos         token.Position
 pub mut:
 	typ      Type      // the type of the const field, it can be any type in V
 	comments []Comment // comments before current const field
@@ -306,6 +307,7 @@ pub struct ConstDecl {
 pub:
 	is_pub bool
 	pos    token.Position
+	attrs  []Attr // tags like `[markused]`, valid for all the consts in the list
 pub mut:
 	fields       []ConstField // all the const fields in the `const (...)` block
 	end_comments []Comment    // comments that after last const field
@@ -460,6 +462,7 @@ pub:
 	is_exported     bool           // true for `[export: 'exact_C_name']`
 	is_keep_alive   bool           // passed memory must not be freed (by GC) before function returns
 	is_unsafe       bool           // true, when [unsafe] is used on a fn
+	is_markused     bool           // true, when an explict `[markused]` tag was put on a fn; `-skip-unused` will not remove that fn
 	receiver        StructField    // TODO this is not a struct field
 	receiver_pos    token.Position // `(u User)` in `fn (u User) name()` position
 	is_method       bool
@@ -484,8 +487,8 @@ pub mut:
 	return_type       Type
 	return_type_pos   token.Position // `string` in `fn (u User) name() string` position
 	has_return        bool
-	should_be_skipped bool
-	has_await         bool           // 'true' if this function uses JS.await
+	should_be_skipped bool           // true, when -skip-unused could not find any usages of that function, starting from main + other known used functions
+	has_await         bool // 'true' if this function uses JS.await
 	//
 	comments      []Comment // comments *after* the header, but *before* `{`; used for InterfaceDecl
 	next_comments []Comment // coments that are one line after the decl; used for InterfaceDecl
@@ -525,7 +528,7 @@ pub mut:
 	left_type          Type // type of `user`
 	receiver_type      Type // User
 	return_type        Type
-	should_be_skipped  bool
+	should_be_skipped  bool   // true for calls to `[if someflag?]` functions, when there is no `-d someflag`
 	concrete_types     []Type // concrete types, e.g. <int, string>
 	concrete_list_pos  token.Position
 	free_receiver      bool // true if the receiver expression needs to be freed
@@ -596,7 +599,7 @@ pub mut:
 	//   [11, 12, 13] <- cast order (smartcasts)
 	//        12 <- the current casted type (typ)
 	pos        token.Position
-	is_used    bool
+	is_used    bool // whether the local variable was used in other expressions
 	is_changed bool // to detect mutable vars that are never changed
 	//
 	// (for setting the position after the or block for autofree)
@@ -624,10 +627,11 @@ pub:
 
 pub struct GlobalField {
 pub:
-	name     string
-	has_expr bool
-	pos      token.Position
-	typ_pos  token.Position
+	name        string
+	has_expr    bool
+	pos         token.Position
+	typ_pos     token.Position
+	is_markused bool // an explict `[markused]` tag; the global will NOT be removed by `-skip-unused`
 pub mut:
 	expr     Expr
 	typ      Type
@@ -638,8 +642,8 @@ pub struct GlobalDecl {
 pub:
 	mod      string
 	pos      token.Position
-	is_block bool // __global() block
-	attrs    []Attr
+	is_block bool   // __global() block
+	attrs    []Attr // tags like `[markused]`, valid for all the globals in the list
 pub mut:
 	fields       []GlobalField
 	end_comments []Comment
diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index a5e0427ff3..39b45d747b 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -776,6 +776,7 @@ mut:
 }
 
 pub fn (mut f Fmt) const_decl(node ast.ConstDecl) {
+	f.attrs(node.attrs)
 	if node.is_pub {
 		f.write('pub ')
 	}
diff --git a/vlib/v/markused/markused.v b/vlib/v/markused/markused.v
index 5d0102efd1..12ce4e15f6 100644
--- a/vlib/v/markused/markused.v
+++ b/vlib/v/markused/markused.v
@@ -336,6 +336,9 @@ pub fn mark_used(mut table ast.Table, pref &pref.Preferences, ast_files []&ast.F
 		pref: pref
 	}
 	// println( all_fns.keys() )
+	walker.mark_markused_fns() // tagged with `[markused]`
+	walker.mark_markused_consts() // tagged with `[markused]`
+	walker.mark_markused_globals() // tagged with `[markused]`
 	walker.mark_exported_fns()
 	walker.mark_root_fns(all_fn_root_names)
 
diff --git a/vlib/v/markused/walker.v b/vlib/v/markused/walker.v
index 54a5a25c7f..a9307b431c 100644
--- a/vlib/v/markused/walker.v
+++ b/vlib/v/markused/walker.v
@@ -72,6 +72,30 @@ pub fn (mut w Walker) mark_exported_fns() {
 	}
 }
 
+pub fn (mut w Walker) mark_markused_fns() {
+	for _, mut func in w.all_fns {
+		if func.is_markused {
+			w.fn_decl(mut func)
+		}
+	}
+}
+
+pub fn (mut w Walker) mark_markused_consts() {
+	for ckey, mut constfield in w.all_consts {
+		if constfield.is_markused {
+			w.mark_const_as_used(ckey)
+		}
+	}
+}
+
+pub fn (mut w Walker) mark_markused_globals() {
+	for gkey, mut globalfield in w.all_globals {
+		if globalfield.is_markused {
+			w.mark_global_as_used(gkey)
+		}
+	}
+}
+
 pub fn (mut w Walker) stmt(node ast.Stmt) {
 	match mut node {
 		ast.EmptyStmt {}
diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index 9f40dff6fb..192f759bc0 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -180,6 +180,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 	mut is_noreturn := false
 	mut is_ctor_new := false
 	mut is_c2v_variadic := false
+	mut is_markused := false
 	for fna in p.attrs {
 		match fna.name {
 			'noreturn' { is_noreturn = true }
@@ -193,6 +194,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 			'trusted' { is_trusted = true }
 			'c2v_variadic' { is_c2v_variadic = true }
 			'use_new' { is_ctor_new = true }
+			'markused' { is_markused = true }
 			else {}
 		}
 	}
@@ -496,6 +498,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 		is_test: is_test
 		is_keep_alive: is_keep_alive
 		is_unsafe: is_unsafe
+		is_markused: is_markused
 		//
 		attrs: p.attrs
 		is_conditional: conditional_ctdefine_idx != -1
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 719f311ac5..2c25c3a47e 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -13,9 +13,7 @@ import v.errors
 import os
 import hash.fnv1a
 
-pub const (
-	builtin_functions = ['print', 'println', 'eprint', 'eprintln', 'isnil', 'panic', 'exit']
-)
+pub const builtin_functions = ['print', 'println', 'eprint', 'eprintln', 'isnil', 'panic', 'exit']
 
 pub struct Parser {
 	pref &pref.Preferences
@@ -3009,6 +3007,18 @@ fn (mut p Parser) import_syms(mut parent ast.Import) {
 
 fn (mut p Parser) const_decl() ast.ConstDecl {
 	p.top_level_statement_start()
+	mut attrs := []ast.Attr{}
+	if p.attrs.len > 0 {
+		attrs = p.attrs
+		p.attrs = []
+	}
+	mut is_markused := false
+	for ga in attrs {
+		match ga.name {
+			'markused' { is_markused = true }
+			else {}
+		}
+	}
 	start_pos := p.tok.position()
 	is_pub := p.tok.kind == .key_pub
 	if is_pub {
@@ -3055,6 +3065,7 @@ fn (mut p Parser) const_decl() ast.ConstDecl {
 			expr: expr
 			pos: pos.extend(expr.position())
 			comments: comments
+			is_markused: is_markused
 		}
 		fields << field
 		p.table.global_scope.register(field)
@@ -3073,6 +3084,7 @@ fn (mut p Parser) const_decl() ast.ConstDecl {
 		is_pub: is_pub
 		end_comments: comments
 		is_block: is_block
+		attrs: attrs
 	}
 }
 
@@ -3105,6 +3117,15 @@ fn (mut p Parser) global_decl() ast.GlobalDecl {
 		attrs = p.attrs
 		p.attrs = []
 	}
+
+	mut is_markused := false
+	for ga in attrs {
+		match ga.name {
+			'markused' { is_markused = true }
+			else {}
+		}
+	}
+
 	if !p.has_globals && !p.pref.enable_globals && !p.pref.is_fmt && !p.pref.translated
 		&& !p.pref.is_livemain && !p.pref.building_v && !p.builtin_mod {
 		p.error('use `v -enable-globals ...` to enable globals')
@@ -3180,6 +3201,7 @@ fn (mut p Parser) global_decl() ast.GlobalDecl {
 			typ_pos: typ_pos
 			typ: typ
 			comments: comments
+			is_markused: is_markused
 		}
 		fields << field
 		p.table.global_scope.register(field)