separator for multiple serial numbers

We have bundle products that contain multiple serial numbers. When these are displayed in a single line, they are typically difficult to read. We need a separator to enter multiple serial numbers in a single line so that they are displayed one below the other in the customer email and on the thank you page. This will improve readability. The separator could be a <br> or a |.

eg

Code 1: xyz | Code 2: abcd | Code 3: shas

Code 1: xyz <br> Code 2: abcd <br> Code 3: shas

Code 1: xyz

Code 2: abcd

Code 3: shas