Calc Function CONVERT_ADD unit string not explained

I had to use the CONVERT_ADD(value,fromUnit, toUnit) a few times. The Unit Strings provided in the Help section are not explained. I figured out a few my self but some I could not.
Also the Unit “Pica” should be renamed “Point”, that is what the convertion really returns 1/72 of an inch. Pica is 1/72 of a foot.
I don’t know if this is reportable as a bug?

“Pica” is pica points (1/72 inch) for interoperability with other spreadsheet applications. The 1/6 inch would be “pica” (note small letter p) but that isn’t implemented yet.

See also the ODF OpenFormula specification for CONVERT

Danke erAck,
may be You could insert this link into the help-files and the documentation.
The documentation does not even contain the table of the help files.