Blue Planet (esp. War In Heaven) has a habit of incorporating other user-made campaigns into it's own canon through references and shout-outs. I'm trying to figure out how many campaigns are canonical to Blue Planet.
So far I have three definites and two maybes.
Silent Threat: Reborn: [captainobvious]Thanks to the GTCv Marcus Glaive and some facts about the GTI, we already know that BP Canon includes Silent Threat: Reborn instead of Silent Threat[/captainobvious]
Vassago's Dirge: The tech description of the GTC Cretheus is a hint, Toqueville openly refers to the "Vassago Incident", and the opening of Universal Truth is frightenly similar to VD's true ending.
Operation Templar: Refered to by name by the Fedayeen. The plot is

canon anyway, and there's not much difference between the

version and the FSPort version.
Sync and Transcend: Maybe. One fail debrief for Universal Truth refers to the Sync drive and the Transcendant. The question is, is it just a cameo or shout-out, or an actual plot consolidation? The later is scary to think about.
Does anyone else know of any other campaigns that Blue Planet has linked its plot to?