Legend had it that the Independent Systems Alliance—or, more accurately, the former Trade Federation—had a group of B1 battle droids that were different from the rest.
Unlike the usual cheap B1 battle droids, they were exceptionally intelligent and formidable in combat. In fact, each one was even stronger than a heavy battle droid or a shielded Destroyer droid.
Whenever the Independent Systems Alliance sent them into battle, no matter how desperate the situation, they could easily wipe out their enemies and complete their mission! They had earned countless merits in the Alliance's years of hiding and in the wars that followed its resurgence, serving as a true backbone of the organization.
What made these unusual B1 battle droids so special was a mysterious rune printed on the plain metal casing of their cheap little heads: "?"
The strange and miraculous rune was stamped on each of their heads. It was precisely because of it that these otherwise ordinary, dirt-cheap B1 battle droids could unleash terrifying combat power with the equally cheap E-5 blaster rifles in their hands—rifles that didn't even have heat sinks, yet could outperform even Destroyer droids.
Unfortunately, that batch of B1 battle droids had been produced on an assembly line on Geonosis, which had fallen ten years ago. The assembly line had long since been destroyed in the nuclear blast. All the Independent Systems Alliance had left were a small number of units—perhaps a hundred thousand, perhaps a million—that they had managed to ship off the planet during the three days before the fleet of the Hero Federation, the "Grand Republic Army," surrounded it.
Later, they successfully retook Geonosis and returned to power, but they never managed to produce more B1 battle droids like those, even after dismantling dozens of them and copying the miraculous "?" marking!