How do I strike through code in xml files(like the book mentioned)

In the book, it says it is a convention to strike through code instead of delete code but how do I do that? Thanks

When you see code that has a strike through, that’s our convention for the book so that you know what lines of code you need to delete. It’s a convention for the book not the real world.

So, just delete any code that you see with a strikethrough.

Thank you for your help! I misunderstood the context.

I am also confused about this, the conventional to strike through code is there instead of delete code. I don’t know how to do that, Mobdro kindly please help!