When you don't understand something in a customer specification, there are a number of options available to you.
Guess: Hey, maybe you'll guess right. Or maybe not, and you'll waste a lot of time going down the wrong path, or maybe do something that just doesn't work, and get sued.
Ask a bunch of anonymous strangers on the internet: Hey, maybe we'll guess right. Or maybe not, and you'll waste a lot of time going down the wrong path, or maybe do something that just doesn't work, and get sued.
Ask your client for a written clarification. Then you'll know.
