The LNER Encyclopedia

You know every time you pick up a connection u.s.b. or phone charger you have to look to see which way up it goes in sometimes in less light than normal

My tip is white correction fluid on the top side so it doesn't need closer inspection.

Or do you know something better

Ay up, Boris!

The only improvement my evil mind can come up with is to use luminous paint but that is going a bit far......

Mine have a selotape flag that has to hang down or to the right depending on which orifice i'm trying to insert it in.