Coupon payment intervals in bond names

Consider the name of a bond: "American Telephone & Telegraph Co. Convertible 4½s, due 1933"^†. I have some questions about the coupon payment interval information contained in the name:

1. I would like to know if the "s" suffix after the coupon rate really means "semiannual coupon payments". If so, could you point me to an authoritative source that says this? I have always assumed that "s" means "semiannual", but when I tried to verify my knowledge by searching online, I had great difficulty in finding any sources, let alone an authoritative source. I have answered two questions^‡ based on this belief, and I would like a confirmation that it is correct.

2. Other than the "s" suffix for semiannual coupon payments, are there similar notations in use for other coupon payment periods/intervals? For example, "Solvent corp. 5a due 2030" for annual coupon payments, and "Ace corp. 5q due 2050" for quarterly payments. Are these conventions used?

3. Are these coupon payment interval conventions specific to the USA? Are they still in use? I ask this because most American corporate bonds I see nowadays have a "%" in place of the "s" (e.g. "The Coca-Cola Company 4.200% Notes due 2050").

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^† I found this bond name in the appendix of Security Analysis (second edition) by Benjamin Graham and David Dodd.

^‡ What is this bond notation? , What does it mean "Cudahy Packing Company 5s, due 1946"?