It looks like this Part has been superseded by LEGO Part 60475b Brick Special 1 x 1 with Clip Vertical [Open O Clip, Hollow Stud].
Click on a colored part below to see the Sets and MOCs that use part 60475a Brick Special 1 x 1 with Clip Vertical [Thick U Clip, Solid Stud] in that color. You can find an overview of all LEGO Colors here.
If a color is missing, it probably needs to be added to a Set Inventory.
This part has been used by MOCs in the following colors but not officially released.