When you need a second thought before plug in the disk-on-key...

Three types of USB plugs. Two of them are easy to pull out: one has an "USB" caption on it and the other is with the USB graphical symbol. The last model is called "simplest" and is not meant to be pulled out without tweezers.

The captioned version looks nice with 0.2mm resolution. Placed standing on the thinner part. Symbol-ed one is for 0.1mm. Placed standing on the thinner part.