Oooh! I just learned this. I've been using the advanced web interface, which has 4 columns, the right one displaying specific requests like user profiles or federated/home feeds. I often search a hashtag and the results appear in that column. The problem is if I do something else, it replaces those results with new content. What I learned today that if I pin that column, it gets added as a new column and the multi-use column appears to its right. Woohoo! (I'm easily delighted.)