Language isolate
The underlying language may be unrelated to any surviving family — a lost isolate or family.
Research compilation
Research compilation from a published ICIT-style digitization — not a complete or licensed photographic corpus
Fit on current defined metric: under investigation.
A live possibility. Absence of a match is not proof of an isolate.
Assumptions
- No surviving descendant is required
- Structural analysis can proceed without a language ID
Strengths
- Does not force a family identification ahead of the evidence
- Historically common for extinct urban languages
Limitations
- Harder to generate lexical tests
- Can be used to postpone falsification