Visually mark requests in Network tab

An option to somehow tag/highlight certain requests (maybe an icon or a color, or a property that can be found in filter textbox) in Network tab, so you don’t waste your time finding that request that you’ve investigated before in a huge list of requests (probably even to the same URL)

A keyboard shortcut/click with modifier key or an easily accessible button for that would be nice, but a context menu item would work too

This request sounds exactly like bug 1656723.