```python
mapping = {
    "direct-indirect evap": "unknown",
    "directcore powered bitfury chips": "unknown", # No exact match but could refer to Bitfury hardware
    "directv connection": "unknown",
    "disc cutter": "unknown",
    "discrete gpu": "unknown",
    "dishwasher": "unknown",
    "display": "unknown",
    "display card": "unknown",
    "display driver": "unknown",
    "display gpu": "unknown",
    "distribution panel": "unknown",
    "distribution panels (208/120 breaker panels)": "unknown",
    "diy board": "unknown",
    "diy board design": "unknown",
    "diy pcbs": "unknown",
    "diy s2 kit": "antminer s2", # Assuming a DIY kit for Antminer S2
    "diy/self-sourced boards": "unknown",
    "diy0": "unknown",
    "diy1": "unknown",
    "diy1 sets": "unknown",
    "diy2": "unknown",
    "dlink 7 port hub": "unknown",
    "dlink 7 ports": "unknown",
    "dlink 7 prot hub": "unknown",
    "dlink 7-port 2.0 usb powered hub": "unknown",
    "dlink 7port hubs": "unknown",
    "dlink 7ports": "unknown",
    "dlink dub-h7 7-port usb hub": "unknown",
    "dlink dub-h7 powered usb 2.0 hub": "unknown",
    "dlink powered hub": "unknown",
    "dlink router": "unknown",
    "dlink switch": "unknown",
    "dlink usb hub": "unknown",
    "dm gui": "unknown",
    "dmm": "unknown",
    "dna1": "unknown",
    "dns server vm": "unknown",
    "docking station": "unknown",
    "dog trixie": "unknown",
    "dogie's sample": "unknown",
    "dongle": "unknown",
    "door stoppers": "unknown",
    "doors": "unknown",
    "dorito cpu": "unknown",
    "dota 2 session": "unknown",
    "double cards": "unknown",
    "double gpu rig": "unknown",
    "double pci-e double cable": "unknown",
    "downloaded files": "unknown",
    "dp210x device": "unknown",
}
```