More thoughts on bug 30708 and the "train" meaning/confusion. One important thing to keep in mind is the BULAC (and maybe others) will want "train". If "batch" appears in the translation files, they will be replaced by the general "batch" translation. What we certainly need here, that will fit everybody's need, is to use a context (gettext message context). So that other languages will be able to translate correctly "train", and other English variation (uk, nz, aus, etc.) will be able to translate "train" to "batch" if that makes more sense for the librarians in their country.
A context is a good idea and would totally avoid the "cat" issue :)