I'm going to give 3 examples of numbers being used with letters. All I want to know is if hyphens have to be used with numbers that are attached to letters. Here are a few examples:

1. Donald and Putin had a G20 (or G-20) conversation.

2. My friend bought the new PS4 (or PS-4).

For my final example, I'm going to mention v2, as in version 2.

3. These are v2 (or v-2) plates.

What are the rules for attaching numbers to letters? Are hyphens required?

I'm going to give three examples of numbers being used with letters. All I want to know is if hyphens have to be used with numbers that are attached to letters. Here are a few examples:

1. Donald and Putin had a G20 (or G-20) conversation.

2. My friend bought the new PS4 (or PS-4).

For my final example, I'm going to mention v2, as in version 2.

3. These are v2 (or v-2) plates.

What are the rules for attaching numbers to letters? Are hyphens required?