Manufacturing Date Codes

So I know that with BD products the first number is the year of manufacturing and the last three are the day of said year it was manufactured.  e.g. 5167 would be the 167th day of 2015 (or 05/95 but you should be able to tell apart 10/20 year old products). Also with BD if there is and A in the four digit code it was manufactured in Asia not the USA.  My question is if anyone can explain to me how the codes work/read for Metolius, Wild Country, Fixe, CAMP, etc? I tried to search the interwebs but didn't come up with much and all of Metolius' packing instructions just say that the numbers represent the date. On my Metolius UL Master cams on the top of the stem there is a letter followed by two digits. (B17) I assume 2017 but am not sure what the B means? Caribiners seem to have a four digit code but doesn't appear to follow the BD style for dating.  Thanks in advance.