kA^2s

J/Ω looks a very good idea, as it avoids any exponent. Then kJ/Ω works without confusion.

Yes, k A²s with the definite space strikes me as clear (10³ A²s). However, this is not what is written in the IEC table that I showed - that has no space. And it appears that a space here would not be permitted by the SI rules, as prefixes are "attached to unit symbols without a space between the prefix symbol and the unit symbol". Note also the point about milli and metre having the same letter, which could lead to confusion in some cases if prefixes were left standing about by themselves. So, for an organization that strives to follow SI, I think replacing k with 10³ would be the safest option to avoid ambiguity. If it's happy to bend the rules a bit in this case, like others Graham mentioned, then the space is probably clear enough, and parentheses even safer.

(On eV: the reason there's an e in the symbol is as you mention. But if we use the symbol in the way the SI system tells us [Table 8] it's a single symbol, regardless of its history. If we wanted to write an electronic charge multiplied by a volt, the former would be a quantity symbol rather than a unit, so would conventionally be italic.)

I suspect our difference here arises because you're considering what would be clear to a technical user, and I'm considering from the view of what happens if SI rules are strictly applied. If we go back to the original question, note that there was no space after the k in the table, which leaves us with the kA² versus mm² point that Andy has summarised well.


[Edit! Now I've seen the update [mapj1] and further point [ebee], after posting. As long as the Americans keep dollar signs before numbers I suppose we're safe with our habits in that way.]

J/Ω looks a very good idea, as it avoids any exponent. Then kJ/Ω works without confusion.

Yes, k A²s with the definite space strikes me as clear (10³ A²s). However, this is not what is written in the IEC table that I showed - that has no space. And it appears that a space here would not be permitted by the SI rules, as prefixes are "attached to unit symbols without a space between the prefix symbol and the unit symbol". Note also the point about milli and metre having the same letter, which could lead to confusion in some cases if prefixes were left standing about by themselves. So, for an organization that strives to follow SI, I think replacing k with 10³ would be the safest option to avoid ambiguity. If it's happy to bend the rules a bit in this case, like others Graham mentioned, then the space is probably clear enough, and parentheses even safer.

(On eV: the reason there's an e in the symbol is as you mention. But if we use the symbol in the way the SI system tells us [Table 8] it's a single symbol, regardless of its history. If we wanted to write an electronic charge multiplied by a volt, the former would be a quantity symbol rather than a unit, so would conventionally be italic.)

I suspect our difference here arises because you're considering what would be clear to a technical user, and I'm considering from the view of what happens if SI rules are strictly applied. If we go back to the original question, note that there was no space after the k in the table, which leaves us with the kA² versus mm² point that Andy has summarised well.


[Edit! Now I've seen the update [mapj1] and further point [ebee], after posting. As long as the Americans keep dollar signs before numbers I suppose we're safe with our habits in that way.]