Comment 3 for bug 413632

As a starting point, I would propose:

 * po files exported by LP/Rosetta should always contain the correct plural forms in the meta data, whether or not there are plural messages (msgids) in the po file
 * If necessary, scripts or other output options could produce po files that do not have this, if it is not supported under different gettext versions
 * gettext msginit should also always add the language specific plural forms to generated po files

In general, if the plural form is *always* present, it enables people to identify problematic po files (for example, where there is a plural msgidand there is no plural form in the header), and encourages adoption of proper plural form usage in software (source strings) and in the translation community. It might also simply logic: always add it instead of checking for plural msgids.