Plural form of rupiah

Plural form of rupiah

In my letter to the editor on corruption What's the motive of
corruption?, which you published on Jan 10, 2001, I wrote
billions of rupiahs (the plural of rupiah) and millions of
rupiahs (again the plural form). You have edited these into
billions of rupiah (without s) and millions of rupiah (again
without s).

With all due respect to your editing capabilities, I think
both corrections are faulty, or are these typographical errors?
By comparison, do we say millions of dollars or millions of
dollar? Hundreds of books or hundreds of book? Can you enlighten
me on this point?

This may be a small matter, but for me it is fundamental,
because I teach English, and my colleagues or students who read
my letter might think that I am sloppy.

RUDI WILSON

Bandung

Note: Both rupiahs and rupiah are correct (as plural form) after
millions/billions of. The Post uses rupiah to be consistent with
the style it has adopted.

--Editor