In the user JSON schema there is a property named preferredContactType which contains a numeric value. The values appear to be hard-coded and there is no lookup table for it.
Please add a table along the lines of
And a web API such as /contact-types to query the values.
Also consider changing the ids to UUIDs as is requested in MODUSERS-123. If nothing else, it would be useful to have a lookup table for the contact types, even if it only contains static values.