diff --git a/models/characteristics.go b/models/characteristics.go
index 503a49f..3be62b6 100644
--- a/models/characteristics.go
+++ b/models/characteristics.go
@@ -28,10 +28,12 @@ func (c *CharacteristicBase) PreUpdate(e modl.SqlExecutor) error {
 	return nil
 }
 
+// UpdateError satisfies base interface.
 func (c *CharacteristicBase) UpdateError() error {
 	return errors.ErrCharacteristicNotUpdated
 }
 
+// DeleteError satisfies base interface.
 func (c *CharacteristicBase) DeleteError() error {
 	return errors.ErrCharacteristicNotDeleted
 }
diff --git a/models/measurements.go b/models/measurements.go
index 827ce31..4fdf733 100644
--- a/models/measurements.go
+++ b/models/measurements.go
@@ -29,10 +29,12 @@ func (m *MeasurementBase) PreUpdate(e modl.SqlExecutor) error {
 	return nil
 }
 
+// UpdateError satisfies base interface.
 func (m *MeasurementBase) UpdateError() error {
 	return errors.ErrMeasurementNotUpdated
 }
 
+// DeleteError satisfies base interface.
 func (m *MeasurementBase) DeleteError() error {
 	return errors.ErrMeasurementNotDeleted
 }
diff --git a/models/species.go b/models/species.go
index e7eb1c6..5bec47c 100644
--- a/models/species.go
+++ b/models/species.go
@@ -29,10 +29,12 @@ func (s *SpeciesBase) PreUpdate(e modl.SqlExecutor) error {
 	return nil
 }
 
+// UpdateError satisfies base interface.
 func (s *SpeciesBase) UpdateError() error {
 	return errors.ErrSpeciesNotUpdated
 }
 
+// DeleteError satisfies base interface.
 func (s *SpeciesBase) DeleteError() error {
 	return errors.ErrSpeciesNotDeleted
 }
diff --git a/models/strains.go b/models/strains.go
index 58e240e..a2389aa 100644
--- a/models/strains.go
+++ b/models/strains.go
@@ -29,10 +29,12 @@ func (s *StrainBase) PreUpdate(e modl.SqlExecutor) error {
 	return nil
 }
 
+// UpdateError satisfies base interface.
 func (s *StrainBase) UpdateError() error {
 	return errors.ErrStrainNotUpdated
 }
 
+// DeleteError satisfies base interface.
 func (s *StrainBase) DeleteError() error {
 	return errors.ErrStrainNotDeleted
 }
diff --git a/models/users.go b/models/users.go
index a4c36ff..d9cf9bb 100644
--- a/models/users.go
+++ b/models/users.go
@@ -30,10 +30,12 @@ func (u *UserBase) PreUpdate(e modl.SqlExecutor) error {
 	return nil
 }
 
+// UpdateError satisfies base interface.
 func (u *UserBase) UpdateError() error {
 	return errors.ErrUserNotUpdated
 }
 
+// DeleteError satisfies base interface.
 func (u *UserBase) DeleteError() error {
 	return errors.ErrUserNotDeleted
 }