diff --git a/random.go b/random.go
index 3a3f16b..2478c75 100644
--- a/random.go
+++ b/random.go
@@ -14,14 +14,33 @@ import (
 const cr = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
 
 // Bitmask sizes for the string generators (based on 93 chars total)
+//
+// These constants define bitmask-related values used for efficient random string generation.
+// The bitmask operates over 93 possible characters, and the constants help determine the
+// number of bits and indices used in the process.
 const (
-	letterIdxBits = 7                    // 7 bits to represent a letter index
-	letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
-	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
+	// letterIdxBits: Number of bits (7) needed to represent a letter index.
+	letterIdxBits = 7
+	// letterIdxMask: Bitmask to extract letter indices (all 1-bits for letterIdxBits).
+	letterIdxMask = 1<<letterIdxBits - 1
+	// letterIdxMax: The maximum number of letter indices that fit in 63 bits.
+	letterIdxMax = 63 / letterIdxBits
 )
 
-// randomStringSecure returns a random, string of length characters. This method uses the
-// crypto/random package and therfore is cryptographically secure
+// randomStringSecure returns a random string of the specified length.
+//
+// This function generates a cryptographically secure random string of the given length using
+// the crypto/rand package. It ensures that the randomness is secure and suitable for
+// cryptographic purposes. The function reads random bytes, converts them to indices within
+// a character range, and builds the string. If an error occurs while reading from the random
+// pool, it returns the error.
+//
+// Parameters:
+//   - length: The length of the random string to be generated.
+//
+// Returns:
+//   - A randomly generated string.
+//   - An error if the random generation fails.
 func randomStringSecure(length int) (string, error) {
 	randString := strings.Builder{}
 	randString.Grow(length)
diff --git a/random_119.go b/random_119.go
index 4b45c55..98d761c 100644
--- a/random_119.go
+++ b/random_119.go
@@ -12,7 +12,17 @@ import (
 	"time"
 )
 
-// randNum returns a random number with a maximum value of length
+// randNum returns a random number with a maximum value of maxval.
+//
+// This function generates a random integer between 0 and maxval (exclusive). It seeds the
+// random number generator with the current time in nanoseconds to ensure different results
+// each time the function is called.
+//
+// Parameters:
+//   - maxval: The upper bound for the random number generation (exclusive).
+//
+// Returns:
+//   - A random integer between 0 and maxval. If maxval is less than or equal to 0, it returns 0.
 func randNum(maxval int) int {
 	if maxval <= 0 {
 		return 0
diff --git a/random_121.go b/random_121.go
index b401bc8..ea1e399 100644
--- a/random_121.go
+++ b/random_121.go
@@ -11,7 +11,17 @@ import (
 	"math/rand"
 )
 
-// randNum returns a random number with a maximum value of length
+// randNum returns a random number with a maximum value of maxval.
+//
+// This function generates a random integer between 0 and maxval (exclusive). If maxval is less
+// than or equal to 0, it returns 0. The random number generator uses the default seed provided
+// by the rand package.
+//
+// Parameters:
+//   - maxval: The upper bound for the random number generation (exclusive).
+//
+// Returns:
+//   - A random integer between 0 and maxval. If maxval is less than or equal to 0, it returns 0.
 func randNum(maxval int) int {
 	if maxval <= 0 {
 		return 0
diff --git a/random_122.go b/random_122.go
index 9a6132b..27ded3d 100644
--- a/random_122.go
+++ b/random_122.go
@@ -12,8 +12,16 @@ import (
 )
 
 // randNum returns a random number with a maximum value of maxval.
-// go-mail compiled with Go 1.22+ will make use of the novel math/rand/v2 interface
-// Older versions of Go will use math/rand
+//
+// This function generates a random integer between 0 and maxval (exclusive). It utilizes
+// the math/rand/v2 interface for Go 1.22+ and will default to math/rand for older Go versions.
+// If maxval is less than or equal to 0, it returns 0.
+//
+// Parameters:
+//   - maxval: The upper bound for the random number generation (exclusive).
+//
+// Returns:
+//   - A random integer between 0 and maxval. If maxval is less than or equal to 0, it returns 0.
 func randNum(maxval int) int {
 	if maxval <= 0 {
 		return 0