Originally I'm thinking of making a phoneme inventory generator.
In order to do that, I need to figure out the commonality of each possible phonemes.
In order to do that, I need to catalogue phonemes of human languages.

I know this has been done before in UPSID, but I'm adding several new fields on my data. The following are the columns I have figured out so far for my table

- Language, self explanatory. This column will be filled with  ISO 639-3 code of the language.
- Phoneme, self explanatory. IPA Unicode will be used to fill this column. I think four character is enough... or is it?
- Nativity, whether the phoneme are native or not. For example /f/ and /z/ are observed in Indonesian, but it's not native.
- Underlying, the underlying representation of the phoneme. For example, many South Asian languages are listed with /n̪ t̪ d̪/ without alveolars to contrast them. The underlying representation of these phonemes would be /n t d/.

Any other column I need to consider in designing the table?