diff --git a/formatter/formatter_dot.go b/formatter/formatter_dot.go
index a503bb3..b3fa744 100644
--- a/formatter/formatter_dot.go
+++ b/formatter/formatter_dot.go
@@ -1,12 +1,14 @@
 package formatter
 
 import (
+	// Used to embed graphviz template file
 	_ "embed"
 	"fmt"
 	"strings"
 	"text/template"
 )
 
+// DotFormatter is used to create Graphviz (dot) format
 type DotFormatter struct {
 	config *Config
 }
@@ -16,22 +18,30 @@ type DotFormatter struct {
 var DotTemplate string
 
 const (
-	DotOpenPortColor     = "#228B22"
+	// DotOpenPortColor defines default color of the opened port
+	DotOpenPortColor = "#228B22"
+	// DotFilteredPortColor defines default color of the filtered port
 	DotFilteredPortColor = "#FFAE00"
-	DotClosedPortColor   = "#DC143C"
-	DotDefaultColor      = "gray"
+	// DotClosedPortColor defies default color of the closed port
+	DotClosedPortColor = "#DC143C"
+	// DotDefaultColor defines default color of various elements (lines, boxes)
+	DotDefaultColor = "gray"
 
+	// DotFontStyle default font style
 	DotFontStyle = "monospace"
 
+	// DotLayout is a type of layout used in Graphviz (dot by default is the most fitting)
 	DotLayout = "dot"
 )
 
+// DotDefaultOptions is a config map that is used in Graphviz template
 var DotDefaultOptions = map[string]string{
 	"default_font":  DotFontStyle,
 	"layout":        DotLayout,
 	"color_default": DotDefaultColor,
 }
 
+// DotTemplateData is a custom TemplateData struct that is used by DotFormatter
 type DotTemplateData struct {
 	NMAPRun   *NMAPRun
 	Constants map[string]string
diff --git a/formatter/nmap_host.go b/formatter/nmap_host.go
index 9d20c39..d57dbc5 100644
--- a/formatter/nmap_host.go
+++ b/formatter/nmap_host.go
@@ -136,9 +136,11 @@ type Hop struct {
 	Host   string `xml:"host,attr"`
 }
 
+// RTT is a separate type that is located in Hop struct
 type RTT float64
 
-// UnmarshalXMLAttr
+// UnmarshalXMLAttr is a separate function that attempts to parse RTT float value
+// if it fails to do so, it sets the value to 0.0
 func (r *RTT) UnmarshalXMLAttr(attr xml.Attr) error {
 	value, err := strconv.ParseFloat(attr.Value, 64)
 	if err != nil {