In the past, I may have said something about making either ring or chain (I forget which) more vulnerable to missiles, or something like that. In yesterday's post about studded leather and splint mail, I inadvertently suggested that ringmail, scalemail, and chainmail provide identical defense. Part of this is because, from what I read in the Ffolkes book on armor, it looks like there wasn't much difference between the protective value of different kinds of mail, just in the quality of the armor. Older mail seems to be mainly scale or various kinds of ring arrangements (including banded mail, which I never knew was actually just a way of arranging rings, scales or splints.) Chain is a more elaborate (and expensive) way of doing the same thing, but making the end product sturdier.
Specifically, ring or scale connect their metal bits with leather or to a cloth/leather garment, while chain is interwoven links that don't use any other material than the metal itself (although it has to be worn over a quilted or leather garment to avoid discomfort.) Therefore, attacks that rot or harm leather (engulfed in flame or ochre jelly) can ruin a suit of ringmail or scalemail, but will leave chainmail basically unharmed.