Spelling - American English vs. British English

This is probably an easy issue to decide, but a factor to take into account when you're considering using a particular vocabulary. There are also some words with alternative spellings in use in one country. It helps to decide on a particular dictionary you will use as the arbiter for disputes.

Spelling is easiest to enforce when all users have the same hardcopy dictionary sitting with them at their data entry site. If this isn't possible, there are many online general reference and specialized dictionaries currently available at no charge.