2.6 - Pressure UOM Issue

[sdeaton75]

There was a unit previously available in 2.5 that is not present in 2.6.

There is lbf/ft2 (psf) but there is not lbf/in2 (psi)
<xs:enumeration value="lbf/ft2">
xs:annotation
xs:documentationpound-force per square foot</xs:documentation>
</xs:annotation>
</xs:enumeration>