US Patent and Trademark Office website, which denotes "Crimson" as being "Computer game software downloadable from a global computer network; Computer game software for use on mobile and cellular phones; Downloadable computer game software via a global computer network and wireless devices." Presumably, whatever "Crimson" is won't be all three of those things.
Interestingly, the filing applies to newly incorporated Bungie Aerospace (rather than Bungie Studios proper), while Bungie's previous trademark applications were all filed by a proxy corporation (as to hide their origins). As with previous reports, we've contacted Bungie for a comment, but don't expect to hear much back. Nor do we expect to hear anything at E3, as the studio has specifically said it won't be attending this year's show.