the printed press style manual standards of writing mandate that liter and meter spelling be used.�
WHOSE style manual is that? Is it the Associated Press Style Manual? Or the federal government style manual? It is not the US Metric Association Style guide.
I don't know for sure about the AP style guide, but I know that some rule (perhaps the federal government style guide, if there is such a thing) requires federal govt. docs to use the meter-liter spelling.
But I also know that the USMA stye guide ("Metric Units of Measure and Style Guide) uses the metre-litre spelling. It does not address this issue by stating it as a rule, but it intrinsically approves the -re spelling by its practice of using it.
I do know that some other publications of USMA are written using the -er spelling because they are used by federal agencies. Federal agencies would not adopt them if the -re spelling were used. USMA gave up the battle on that one in hopes of ultimately winning the war. Even in those publications, however, there is usually a disclaimer someplace stating that the -re spellings are also correct.
Regards, Bill Hooper Fernandina Beach, Florida, USA
