Simple train [lvl4+]

I think I'm just tired. I mean, I seen/saw what it did, and I even viewed the source to know why it does it, but the significance eludes me. Thanks though

Thanks Nyuels. I appreciate the reply.

My problem must be that I am not seeing such. First, I inspect the element, which gives me https://i.imgur.com/dX6cAof.png

Nothing unusual looking about the 7Mk5P its weird selection behavior. I figure the browser optimized it away, so I look at the actual page source. What I find is https://i.imgur.com/FIZz4kF.png

So I see that there are p tags around the 7M, so that would explain the strange selection behavior. Nowhere is there a Right-to-Left mark, so I was moving around the 7 and M, obviously with no luck.