Dell XPS 18 (1820, Early 2014) - Manual (Page 15)

Setting Up Your Computer │ 15
Inserting a Memory Card (Sold Separately)
— Optional
1 Orient the SD card so that the pins on the card are facing the rear
when inserted.
2 Push the slot cover down.
3 Push the SD card into the slot until it clicks into place.
For more information, see “Media-card reader” in Specifications.