Hi climber_grrl! Thank you for such a quick and kind reply

Actually, I'm not into either of those, the name is just the result of bad brainstorming...
Actually, I wen't to my nearest IKEA store and visited the Customer Service/Returns area earlier today (before I wrote the first message) and the salesperson went to look in the "stash" but didn't find any. She said that I had to get the part number also, because she didn't know the part very well. Therefore I went to the IKEA work section and tried to find a desk that had this part on it (and then ask the personal for the manual with the part number), but the T- and A-style legs they're selling now isn't constructed like this. And sadly, there are neither EFFEKTIV nor GALANT instructions on this website
Lastly, I probably should describe a little bit more where the part belongs (I was in a bit of a rush when I wrote the original post).
Oh and by bottom I mean't to say underside... (I'm swedish by the way, see the irony?

)
The wooden board of the desk sits on top of metal rails (crossbars), that are screwed to it to form a rectangle. In each of the four corners (where the ends of the rails meet) there should be a bolt going through a hole that is cut-out in the ends of the rails - from the leg on the outside and to the inside where it's fastened with one of these mysterious parts (that hinges onto holes in the rails) and then a nut on top of it. Now, nuts and bolts I can always get a hold of, but this... this is tougher...
Thanks for all the help so far.... hope someone can help me further on this!
Cheers!
// M