For the second time Goutor mentions using different size cards for different note types, but doesn't specifically advise for it or provide a reason. Perhaps his advice for consistency and card size applies only to cards of particular types? (p28)

link to: https://hypothes.is/a/XPphjkNZEe2s3i9VV4qt1g

Incidentally he also specifically mentions 7x9" cards here too. How frequently used were these as a standard?

While he previously recommended using note cards of the same size, the examples in Goutor (1980) have 3x5" cards for bibliographic notes and 5x7" or larger cards for content notes. (p19, 21)

Is there a reason stated anywhere here for this discrepancy or change? One would ostensibly keep them in different places/sections of one's card index, but does the size difference help to differentiate the two to aid in sorting? Is the larger card intended to hold more long form writing?

Goutor is in Canada, so were 5x7" cards more common or standardized there in the late 1970s and early 80s?

A5 measures 148 × 210 millimeters or 5.83 × 8.27 inches, so is a bit larger than 5x7".

5x7" is a more standard photo size, so was this chosen as the result of storage options from the photography space?

5x7" is scantly available in America in 2022, but only from Hamilco. A few others make cardstock in that size but not specifically as index cards.

This is a combo of Giacomo's list and OS's list. I've devoted one explanation card to each item on this list. Education, savings/investment, and scientific research are featured by both Giacomo & OS; we may want to cut some of the others