When designing a data entry form for entering information about a person or an organization (e.g. customer info, international business partners, etc.), there arises a question about the best way to list nationalities/citizenships in a select box or typeahead.

Consider a form containing both an address section, including a "country" field, and separately a "nationality" field (since one does not necessarily imply the other).

The country field should clearly be backed by a simple list of country names. But I have had arguments over what should be listed in the nationality field. One approach is to just list country names there as well; the other is to use adjectives (e.g. "German" instead of "Germany"). On one hand, nationality and citizenship are probably more naturally expressed with adjectives. On the other hand, certain countries have adjectival forms such that it may be confusing to select that country in the address field, then try and find it in the adjective list, as it may show up in a totally different spot alphabetically.

This is not an issue for most countries, e.g. "Germany" → "German", "Japan" → "Japanese", etc. but there are several exceptions, which can be basically split into two cases:

1. Countries with wordy prefixes, like "United States of America" or "People's Republic of China". "People's Republic" would appear in the "P" section for country, but "Chinese" would appear in the "C" section for nationality. This case isn't as problematic, since most or all cases can be solved by moving prefixes to the end, separated by a comma ("America, United States of", "China, People's Republic of").

2. Countries whose adjectival form is significantly different from the country name, specifically those with a different first letter, e.g. "Netherlands" → "Dutch", "Côte d'Ivoire" → "Ivorian", "El Salvador" → "Salvadoran". This is the bigger point of contention.

The second case is really the one where the conversation gets hung up. It may be that if I'm not aware that "Dutch" is the correct adjective for people from the Netherlands, I probably will be confused if I enter "Netherlands" in the country field, then head to the nationality field and can't find "Netherlandian" or "Netherlandish" or anything else that looks right in the "N" section. "El Salvador" vs. "Salvadoran" is perhaps even more confusing, since a user would be almost correct in assuming they should look for something like "El Salvadoran", not realizing that the "El" is removed, but they will be a hundred items away from the correct adjective.

But with that said, this is certainly a minority case for most countries, and it may be that in the majority of these edge cases, the user is familiar enough to make the leap, or will be able to find out quickly enough.

So I'm unsure where I stand. Should a Nationality list use country names, or adjectives? Which will provide the better user experience overall?