It’s stupid. For one thing you use them in increments of six which makes holding fifteen seem like a rather arbitrary number. Also it would have been nice to know that I could only hold fifteen Modulus Reports before I turned in about thirty two reports between my three characters only to find out that I was capped out at the aforementioned fifteen and that the other seventeen reports vanished right down the crapper. Thanks Bungie for screwing me over - yet again. “Bungie, thou art shadier than an Ahamkara”.