diff --git a/pkg/obiseq/class.go b/pkg/obiseq/class.go
index c9dc060..8ccb95d 100644
--- a/pkg/obiseq/class.go
+++ b/pkg/obiseq/class.go
@@ -9,6 +9,16 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+// Defines an object able to classify a sequence in classes defined by an integer index.
+//
+// The first function is the classifier itself. It takes a BioSequence and returns
+// an integer. The integer is the class of the BioSequence.
+//
+// The second function is the classifier's value function. It takes an integer and
+// returns a string. The string is the original value used to define the class of the sequence.
+//
+// Moreover a third function resets the classifier, and fourth one
+// returns a clone of the classifier.
 type BioSequenceClassifier struct {
 	Code  func(*BioSequence) int
 	Value func(int) string
diff --git a/pkg/obiseq/join.go b/pkg/obiseq/join.go
index f13f75e..02a40b9 100644
--- a/pkg/obiseq/join.go
+++ b/pkg/obiseq/join.go
@@ -1,5 +1,6 @@
 package obiseq
 
+// A method that concatenates two BioSequences.
 func (sequence *BioSequence) Join(seq2 *BioSequence, inplace bool) *BioSequence {
 
 	if !inplace {
diff --git a/pkg/obiseq/merge.go b/pkg/obiseq/merge.go
index ff17067..6a49094 100644
--- a/pkg/obiseq/merge.go
+++ b/pkg/obiseq/merge.go
@@ -30,6 +30,7 @@ func (sequence *BioSequence) HasStatsOn(key string) bool {
 	return ok
 }
 
+// A function that takes a BioSequence and a key and returns a StatsOnValues.
 func (sequence *BioSequence) StatsOn(key string, na string) StatsOnValues {
 	mkey := StatsOnSlotName(key)
 	annotations := sequence.Annotations()
@@ -75,6 +76,7 @@ func (sequence *BioSequence) StatsOn(key string, na string) StatsOnValues {
 	return stats
 }
 
+// Adding the count of the sequence to the count of the key in the stats.
 func (sequence *BioSequence) StatsPlusOne(key string, toAdd *BioSequence, na string) bool {
 	sval := na
 	annotations := sequence.Annotations()
@@ -122,10 +124,7 @@ func (stats StatsOnValues) Merge(toMerged StatsOnValues) StatsOnValues {
 	return stats
 }
 
-/*
-
-	Merges two sequences
-*/
+// Merging two sequences.
 func (sequence *BioSequence) Merge(tomerge *BioSequence, na string, inplace bool, statsOn ...string) *BioSequence {
 	if !inplace {
 		sequence = sequence.Copy()