DriverBench full_bson.json uses legacy binary type:

[daprahamian]

full_bson.json includes the following segment:

"BOQAeydE": {
  "$binary": "RWNVVkhUUmVsWEhzcnhxV25WdnVQTWFERUJMRFRrYmlOVUFGYmh3QWZzRGtTRkVHT1lrTWFKR2twUUFIZVVGWkJ1Y1RlYlpNTGF2VG51Vk8=",
  "$type": "00"
},

This is the legacy binary format, and should look something like:

"Binary": {
  "$binary": {
    "base64": "RWNVVkhUUmVsWEhzcnhxV25WdnVQTWFERUJMRFRrYmlOVUFGYmh3QWZzRGtTRkVHT1lrTWFKR2twUUFIZVVGWkJ1Y1RlYlpNTGF2VG51Vk8=",
    "subType": "03"
  }
},

[mbroadst]

/cc @xdg

[behackett]

subtype 03 is for legacy UUID, not legacy generic binary.

[xdg]

I think he meant "legacy extended json binary type" -- but in the second example I think it should be subtype 0, not 03 for consistency. The keys are different (and in a subdoc) but the content is the same.

[daprahamian]

I actually wound up using subtype 0 in #291.