I've been collecting FDCs pretty passively via a standing order with the
Canada Post Philatelic Service since 1982, so yeah, I get Collections and Details. You're right that one or both of those publications do have some ordering info, but neither one has quite the details about the collections (see what I did there?) that appears in the 'productlisting.pdf' document. I want to know what OFDCs have been made available since mid-2007, and the Product Listing seems to be the only thing that has the specific detail (e.g. confirmation that UL, LL, UR, and LR plate block OFDCs exist, or don't) I'm after.
It seems to be possible to mostly figure it out from the product numbers, but not completely: a product number ending in -121 seems to ensure that plate blocks (products -122, -123, -124, and -125) exist; a product number ending in -131 means only a single or combination OFDC (no plate blocks); -144 means a souvenir sheet only (no singles, combos, or plate blocks). That's all pretty easy to decipher into a mostly-complete checklist. However, product codes ending in -126 seem to be used for combination OFDCs both with and without plate blocks being issued. Annoying! Which is why I'd rather not have to sort it out from limited info -- I'd much prefer the information to be definitive (heh), right from the Product Listing documents.
I also don't know -- maybe somebody can confirm or refute? -- whether the Product Listing also exists (or existed) on paper. Maybe somebody's got old ones they could snap pics of, say?? Any help would be appreciated....
(And thanks for the welcome to SCF!)