Ångström is currently approved by NIST for use with the SI, so I don’t think it’s quite in the same category as mmHg and hogs heads and pound force. I agree pm

Ångström is currently approved by NIST for use with the SI, so I don’t think it’s quite in the same category as mmHg and hogs heads and pound force. I agree pm is a better choice than mÅ, but I’m not positive mÅ wouldn’t pass NIST internal review, especially if it’s in common use in the field. https://physics.nist.gov/cuu/Units/outside.html https://physics.nist.gov/cuu/Units/outside.html