The USB symbol goes on top, IIRC.

Edit: ninja'd by an enormous amount of people elsewhere in the thread, gah.

This is not always true, and not all ports are horizontal anyway.

Isn't it part of the standard?

In relation to the PCB, so if they're horizontally mounted onto the motherboard, you end up with vertical slots on the back of a standard tower.

Yes.

Does everyone follow the standard? No. Including big names that prefer to have their logo facing up.

Apple and many others need to be reverse always. There is no top.

Vertically aligned motherboards are hard to judge what "up" is. Usually up is where the expansion boards are plugged in. But not all computer users know how a computer looks inside.

> The USB symbol goes on top, IIRC.

For some values of "top"; that is, some device manufacturers install the socket upside-down.

It doesn't help if you've trying to do it totally blind, but the 2 open square holes go on top, once I figured that out I've never had any issues plugging them in correctly. The only one I have issues with is my keyboard because the pcb in the plug is black and the it's a little hard to tell which side is the open holes and which side is the black pcb.

Heck, just making the plastic insert white instead of black (now sometimes blue, occasionally orange) would have helped.

Frequently (by convention) the colors on the USB ports have meaning (including white actually indicating USB 1.0):

https://duckduckgo.com/?q=colors+on+usb+ports