The BD5 sits on a crate. Red light pulsing. (the British revolutionary ghost) hovers nearby, annoyed.
The term in this context most likely refers to a specific digital file quality—specifically a Blu-ray (BD) 5 rip. In video encoding, a BD5 is a high-definition release that has been compressed to fit on a standard 4.7 GB DVD-R while maintaining much of the Blu-ray’s original visual fidelity. Plot Breakdown: Ghosts (US) S04E01 – "Patience" ghosts s04e01 bd5
There are both UK and US versions of "Ghosts," with the UK version being the original. The US adaptation brings a similar concept to American audiences. The episode you're referring to could be from either version. The BD5 sits on a crate