Originally Posted by Pleiades

Yes, it is the braided hose that needs blocking or clamping.

That "T" connector in the air intake pressure sensor vacuum line is normally connected to something I hope? Looks suspiciously like someone has tried to block it with some sort of goo? Maybe you have a Scottoiler fitted and the vacuum take-off was removed in the photo, or perhaps it did have one fitted and a previous owner has attempted to block the connector?

As for the airbox drain, I can't understand why anyone would block it off? It does still have the rubber bung in the other end? If I were you, I'd unblock it as it is the only visual tell-tale that you have water or oil in the airbox. I know you don't at the moment, but best to prepare for the future.