Type A vs. Type L

Type A is the ungrounded 2-flat-pin plug standard in North America, Central America, and Japan -- NEMA 1-15, rated 15A/125V. It's a physical subset of Type B: any Type A plug fits directly into a Type B socket, the ground pin recess simply unused.

Type L, Italy's standard, uses three round pins in a straight line rather than a triangle, in two incompatible sizes (10A and 16A). Chile and Uruguay use the same physical design, though no independently confirmed national standard document defines it in either country.