Symbols on jets? What do they mean?

[02silverpile]

So, I removed the main jet out of my 39mm FCR the other day. I noticed it had a 158(rd, or DR). My question is what does the rd or dr suffix stand for? I know if there is a star on the jet its usually a keihin bran jet. There are also DJ that mean dyno jet. I have not seen this before, just looking for a little help, so if I rejet, I can cross reference the correct size. Thanks.

[GPracer2500]

RD branded jets are made by RD Precision. They are Keihin copy-cats and use the same scale as factory Keihins.