I basically discovered the i.col notation by accident. I've even asked a question on so about it (as I wasn't sure if it was kosher!). see here

I haven't seen in either the FAQ, the intro or the cheat sheet. I haven't finished yet the data camp course on data table but it wasn't in any part of the training I've done so far (incidentally, I would love to give you guys some feedback on the training, but I'm not sure where to do it).

Would it be possible to add examples of the i.col notation to the examples and (all the) docs please?