[Lucien Nunes]

Is your smeared code actually TDS = wk 48 1955? Not that it makes much difference relative to TIS, but I can resolve that middle character as a D quite convincingly

The capacitor with date code BBB was clearly a Hunts product but was branded RTC, i.e. a subcontract job for which the letter B might have conveyed some other information than the date. What information, and why they didn't want the date code, are other questions. See pic.

What actually deserves a re-visit is the question of later codes (with year digit first) being either Yr Wk Wk or Yr Month Month. As I noted earlier, most yield valid month numbers, which was also the conclusion of a writer on the Vintage Amps forum who listed a selection of caps from late 1960s guitar amps, all of which decoded as a valid month with reasonable distribution. While such codes also yield valid Year Wk Wk results, the distribution would be unrealistic with all manufacture appearing to occur in the first twelve weeks of the year. I linked to that thread on the Vintage Amps forum but the link is now dead and I cannot find a local copy of the content.

But there are some exceptions (such as N WI cited above) which only work in Yr Wk Wk format, since both week 71 and month 13 are invalid. Can we identify a time period for which Yr Wk Wk was used, and /or tighter boundaries on the end of Wk Wk Yr and the start of Yr Month Month?