diff --git a/flag.go b/flag.go
index 60c2038c..e02abfee 100644
--- a/flag.go
+++ b/flag.go
@@ -190,9 +190,15 @@ type Value interface {
 	Type() string
 }
 
+// SliceValue is a secondary interface to all flags which hold a list
+// of values.  This allows full control over the value of list flags,
+// and avoids complicated marshalling and unmarshalling to csv.
 type SliceValue interface {
+	// Append adds the specified value to the end of the flag value list.
 	Append(string) error
+	// Replace will fully overwrite any data currently in the flag value list.
 	Replace([]string) error
+	// GetSlice returns the flag value list as an array of strings.
 	GetSlice() []string
 }