Required. <Sprite> is the variable you prepared with AddSprite().
Example:
Dim sprites(5) As Integer
For i = 0 To 5
sprites(i) = AddSprite(1,1)
PropSprite sprites(i),1,0
MoveSprite sprites(i),136+(i<<4),136
Next
Locate 4,0: Print "Press Start to clear some sprites"
While 1
j = JoyPad(0)
If j.7 Then
FreeSprite sprites(5)
FreeSprite sprites(3)
Exit While
End If
Wend