NP, we all had to learn at some point, right?
We make the holes in a carto for placement in a tank. The tank holds lots of extra juice, and the holes in the carto allow the juice to absorb into the carto from the tank.
See this link as an example (just a quick one I knew where to find - I'm not recommending it necessarily, as I haven't tried this particular one, although I do like this supplier. ).
HV Chibi Tank Mod
A good photo - shows the carto w/the holes. Hope this helps!
Thanks for the explanation, that is one use I never would have guessed.