diff --git a/.gitignore b/.gitignore
index 824187c..70762f3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 .env
 .env.*
 !.env.example
+env.*
 
 dist/
 bin/
diff --git a/README.md b/README.md
index f0942fc..9586c3e 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,35 @@
 * Filtering by key/prefix/groups when printing keys.
 * Literal (what you see is what you get) or interpolated (shell-like interpolation of variables) modes.
 
+## Example
+
+```shell
+# Crate a new env file
+touch env.test
+
+# Create a key/pair value
+dottie --file env.test set my_key value
+
+# Create another key/pair value with two comments (one is validation that the value must be a number)
+dottie --file env.test set --comment 'first line' --comment '@dottie/validate number' my_int 123
+
+# Check validation (success)
+dottie --file env.test validate
+
+# Print the file
+dottie --file env.test print
+
+# Print the file (but pretty)
+dottie --file env.test print --pretty
+
+# Change the "my_int" key to a non-number
+# NOTE: the comments are kept even if they are omitted here
+dottie --file env.test set my_int test
+
+# Test validation again
+dottie --file env.test validate
+```
+
 ## Install
 
 ### homebrew tap
diff --git a/cmd/cmd_print.go b/cmd/cmd_print.go
index 2777a8f..ba2b955 100644
--- a/cmd/cmd_print.go
+++ b/cmd/cmd_print.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"os"
 
-	"github.com/davecgh/go-spew/spew"
 	"github.com/jippi/dottie/pkg/tui"
 	"github.com/urfave/cli/v3"
 )
@@ -14,9 +13,6 @@ var printCommand = &cli.Command{
 	Usage:  "Print environment variables",
 	Before: setup,
 	Action: func(_ context.Context, _ *cli.Command) error {
-		spew.Config.DisablePointerMethods = true
-		spew.Config.DisableMethods = true
-
 		settings.Interpolate = true
 
 		tui.Theme.Dark.Printer(tui.Renderer(os.Stdout)).Println(env.Render(*settings))
diff --git a/cmd/cmd_set.go b/cmd/cmd_set.go
index 86d4bbe..f0a3d5e 100644
--- a/cmd/cmd_set.go
+++ b/cmd/cmd_set.go
@@ -58,7 +58,7 @@ var setCommand = &cli.Command{
 			Comments:       cmd.StringSlice("comment"),
 		}
 
-		assignment := ast.Assignment{
+		assignment := &ast.Assignment{
 			Name:    key,
 			Literal: cmd.Args().Get(1),
 			Active:  !cmd.Bool("commented"),
@@ -66,7 +66,7 @@ var setCommand = &cli.Command{
 
 		assignment.SetQuote(cmd.String("quote-style"))
 
-		_, err := env.Set(&assignment, options)
+		_, err := env.Set(assignment, options)
 		if err != nil {
 			return err
 		}
diff --git a/cmd/main.go b/cmd/main.go
index 4fa6bab..69ef8a0 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -27,9 +27,6 @@ var (
 func main() {
 	__load()
 
-	// spew.Config.DisableMethods = true
-	// spew.Config.DisablePointerMethods = true
-
 	origHelpPrinterCustom := cli.HelpPrinterCustom
 	defer func() {
 		cli.HelpPrinterCustom = origHelpPrinterCustom
@@ -66,5 +63,8 @@ func main() {
 }
 
 func __load() {
+	spew.Config.DisablePointerMethods = true
+	spew.Config.DisableMethods = true
+
 	spew.Dump()
 }
diff --git a/pkg/ast/document.go b/pkg/ast/document.go
index c752fa5..5525acb 100644
--- a/pkg/ast/document.go
+++ b/pkg/ast/document.go
@@ -2,6 +2,7 @@
 package ast
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"reflect"
@@ -112,22 +113,16 @@ func (doc *Document) Set(input *Assignment, options SetOptions) (bool, error) {
 			return false, fmt.Errorf("Key [%s] does not exists", input.Name)
 		}
 
-		group = doc.GetGroup(RenderSettings{FilterGroup: options.Group})
-		if group == nil {
-			group = &Group{
-				Name: input.Group.Name,
-			}
-
-			doc.Groups = append(doc.Groups, group)
-		}
+		group = doc.EnsureGroup(options.Group)
 
 		existing = &Assignment{
-			Name:  input.Name,
-			Group: group,
+			Name:    input.Name,
+			Literal: input.Literal,
+			Active:  input.Active,
+			Group:   group,
 		}
 
-		switch {
-		case len(options.Before) > 0:
+		if len(options.Before) > 0 {
 			before := options.Before
 
 			var res []Statement
@@ -148,9 +143,20 @@ func (doc *Document) Set(input *Assignment, options SetOptions) (bool, error) {
 			}
 
 			group.Statements = res
+		}
 
-		default:
+		if group != nil {
 			group.Statements = append(group.Statements, existing)
+		} else {
+			idx := len(doc.Statements) - 1
+
+			// if laste statement is a newline, replace it with the new assignment
+			if idx > 1 && doc.Statements[idx].Is(&Newline{}) {
+				doc.Statements[idx] = existing
+			} else {
+				// otherwise append it
+				doc.Statements = append(doc.Statements, existing)
+			}
 		}
 	}
 
@@ -169,6 +175,22 @@ func (doc *Document) Set(input *Assignment, options SetOptions) (bool, error) {
 	return true, nil
 }
 
+func (doc *Document) EnsureGroup(name string) *Group {
+	if len(name) == 0 {
+		return nil
+	}
+
+	group := doc.GetGroup(RenderSettings{FilterGroup: name})
+
+	if group == nil && len(name) > 0 {
+		group = &Group{
+			Name: "# " + name,
+		}
+	}
+
+	return group
+}
+
 func (d *Document) GetConfig(name string) (string, error) {
 	for _, comment := range d.Annotations {
 		if comment.Annotation == nil {
@@ -198,14 +220,35 @@ func (d *Document) GetPosition(name string) (int, *Assignment) {
 func (d *Document) RenderFull() string {
 	return d.Render(RenderSettings{
 		IncludeCommented: true,
+		Interpolate:      false,
 		ShowBlankLines:   true,
 		ShowColors:       false,
 		ShowComments:     true,
 		ShowGroups:       true,
-		Interpolate:      false,
 	})
 }
 
 func (d *Document) Render(config RenderSettings) string {
-	return renderStatements(d.Statements, config)
+	var buf bytes.Buffer
+
+	root := renderStatements(d.Statements, config)
+	if len(root) > 0 {
+		buf.WriteString(root)
+	}
+
+	hasOutput := config.WithGroups() && len(root) > 0
+
+	for _, group := range d.Groups {
+		output := group.Render(config)
+
+		if hasOutput && len(output) > 0 {
+			buf.WriteString("\n")
+		}
+
+		hasOutput = config.WithGroups() && len(output) > 0
+
+		buf.WriteString(output)
+	}
+
+	return buf.String()
 }
diff --git a/pkg/ast/group.go b/pkg/ast/group.go
index 09ae0f9..f4b1498 100644
--- a/pkg/ast/group.go
+++ b/pkg/ast/group.go
@@ -41,9 +41,9 @@ func (g *Group) Render(config RenderSettings) string {
 
 	var buf bytes.Buffer
 
-	res := renderStatements(g.Statements, config)
+	rendered := renderStatements(g.Statements, config)
 
-	if config.WithGroups() && len(res) > 0 {
+	if config.WithGroups() && len(rendered) > 0 {
 		if config.WithColors() {
 			out := tui.Theme.Info.Printer(tui.RendererWithTTY(&buf))
 			out.Println("################################################################################")
@@ -62,7 +62,7 @@ func (g *Group) Render(config RenderSettings) string {
 	}
 
 	// Render the statements attached to the group
-	buf.WriteString(res)
+	buf.WriteString(rendered)
 
 	return buf.String()
 }
diff --git a/pkg/ast/new_line.go b/pkg/ast/new_line.go
index edc05fe..7985b39 100644
--- a/pkg/ast/new_line.go
+++ b/pkg/ast/new_line.go
@@ -1,6 +1,8 @@
 package ast
 
-import "reflect"
+import (
+	"reflect"
+)
 
 type Newline struct {
 	Blank    bool   `json:"blank"`
diff --git a/pkg/ast/render_settings.go b/pkg/ast/render_settings.go
index ebf92df..f545560 100644
--- a/pkg/ast/render_settings.go
+++ b/pkg/ast/render_settings.go
@@ -9,11 +9,11 @@ type RenderSettings struct {
 	FilterGroup      string
 	IncludeCommented bool
 
-	ShowPretty     bool
-	ShowComments   bool
-	ShowGroups     bool
 	ShowBlankLines bool
 	ShowColors     bool
+	ShowComments   bool
+	ShowGroups     bool
+	ShowPretty     bool
 
 	Interpolate bool
 }
diff --git a/pkg/ast/shared.go b/pkg/ast/shared.go
index ea973d8..08ed781 100644
--- a/pkg/ast/shared.go
+++ b/pkg/ast/shared.go
@@ -30,25 +30,13 @@ func renderStatements(statements []Statement, config RenderSettings) string {
 	var (
 		buf     bytes.Buffer
 		prev    Statement
-		line    *Newline
 		printed bool
 	)
 
 	for _, stmt := range statements {
 		switch val := stmt.(type) {
 		case *Group:
-			output := val.Render(config)
-			if len(output) == 0 {
-				continue
-			}
-
-			if config.WithBlankLines() && !prev.Is(line) {
-				buf.WriteString("\n")
-			}
-
-			buf.WriteString(output)
-
-			printed = true
+			panic("group should never happen in renderStatements")
 
 		case *Comment:
 			printed = true
@@ -65,12 +53,9 @@ func renderStatements(statements []Statement, config RenderSettings) string {
 			// which mean they are too close in the document, so we will
 			// attempt to inject some new-lines to give them some space
 			if config.WithBlankLines() && val.Is(prev) {
-				switch {
 				// only allow cuddling of assignments if they both have no comments
-				case val.HasComments() || assignmentHasComments(prev):
+				if val.HasComments() || assignmentHasComments(prev) {
 					buf.WriteString("\n")
-
-				default:
 				}
 			}
 
diff --git a/pkg/parser/parser.go b/pkg/parser/parser.go
index 42bb31e..74f4532 100644
--- a/pkg/parser/parser.go
+++ b/pkg/parser/parser.go
@@ -62,9 +62,6 @@ func (p *Parser) Parse() (*ast.Document, error) {
 			// Append the group
 			global.Groups = append(global.Groups, group)
 
-			// Append it to the statements list
-			global.Statements = append(global.Statements, val)
-
 		case *ast.Assignment:
 			val.Position.File = p.filename