Dell XPS 18 (1810, Early 2013) - Manual (Page 15)

Insert an SD Card (optional)
1 Make sure the orientation of the SD card is correct 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 spring-loaded slot until it is locked firmly
into place.
NOTE: The SD-card slot is compatible with Standard-Capacity (SDSC),
High-Capacity (SDHC), the eXtended-Capacity (SDXC) storage cards,
Memory Stick, Memory Stick Pro, MMC, and xD, with a maximum storage
capacity of 2 TB.
Setting Up Your Computer │ 15