SVL = Substitute Voice-Leading
Sometimes it simply sounds better if you don’t stick to the traditional voice-leading guidelines. In composition, there are many opportunities where you want to use SVL over VL. Here are some examples:
=> Parallel movement works great when the distance from one note to the next in your parts is small, like a 1 or 2 (minor or major second).
=> Sometimes, you want to double harmony in a second instrument section, but you want to create contrary motion between those two sections. In this case, let your stronger section follow proper voice-leading and use SVL for the other one.
=> Imagine you want to transition to a different register, but voice-leading won’t let you get there. Switch to SVL in this case.
All of this is part of developing the tools and techniques that will enable you to compose with freedom!