I don't like this advice.
When you ship things to Nikon repair you should remove all non-essential items (lens hoods, filters, tripod collars and plates, etc.), but do leave the front and rear lens cap on. The only exception I make to this rule is if the accessory itself is part of something that needs repair (e.g. the tripod collar is bent or broken). The glass on your lens needs protection, and the caps are the best protection you've got. Nikon should return the lens with caps if you sent it to them that way. I use a Brother P-touch label printer to create small labels I put on everything, and it seems that Nikon always sends back my lens with my caps when they're being serviced.
I should note a couple of other things, though. First, on your repair request, make sure that you indicate that you sent the lens with caps. Usually there's an Supplied Accessories field you can specify that in, but you can always just write something like "50mm f/1.4G lens with front/rear caps" in the Item Description. If Nikon doesn't return your lens with caps, this is what you point to in order to get new caps! Second, while you may be tempted to send your equipment to Nikon in its original box, in almost no case will you get the original box back. Nikon wraps and seals repaired equipment in bubble wrap, and puts that in generic boxes when they return it. So if you want to keep your box, don't send it.