14 are often referred to as planetary-mass objects, but depending on their formation mechanism they are also called planetary-mass brown dwarfs.

In the table of ultracool fundamental parameters there are currently 422 objects with an infrared spectral type of L and a mass range of 14-78.5 . Additionally there are dozens of L-type brown dwarfs known that co-move with a star, white dwarf or brown dwarf. The first L-type brown dwarf discovered was GD 165B,