Post marked with red line on left

My cat walked across my keyboard while reading a thread topic. Now the post I was reading is marked with a vertical red line on the left. What did she do and how do I undo it?

It occured to me that the color of the line is likely to be different in different themes. This is in Sam’s Simple Theme.

Your cat likely stepped on the k or j keys, which are the keyboard shortcuts for moving your selection. Refreshing the page fixes it.

Thanks. That does indeed work. I was afraid it was marking the post as “ignore” or something like that, and I had no intention of doing that.

I would love an ignore this post feature.