# Four-study source provenance and limits

This viewer is an isolated continuation of the preserved Fa v4 viewer. Official MPFB assets retain their source CC0 provenance; project-authored oral, throat, dental and overlay additions remain educational engineering geometry. Detailed inherited source/license records are retained under history/.

The new qualitative ث scope comes only from the supplied Arabic-29-Makhraj-3D-Research-BN-26OCT20.txt §6.04, exact lines 292–308. See THA-SOURCE-REFERENCE.html. Fa's §6.20 page remains separate. The four planned studies are B, Fa, Tha and an open-mouth comparison, not four validated letters.

A17 follows the actual Tongue source and DP_tha_elevate / DP_tha_advance. Four passive A02 references are lingual-incisal crown subsets, distinct from Fa's labial-incisal caps. The head's independent DP_fa_upper_clearance only opens the lip; the Tha clip must not use Fa's lower-lip curl.

The authored analytic scalar envelope is C2, but native keys and exported playback use 100-Hz piecewise-linear samples. The timeline is authored, not measured speech timing. Finite geometry and source-binding tests are separate from browser observation and scientific validity. No physical gap/contact area/pressure/airflow, pronunciation, audio or expert approval is claimed.

Current artifact identity is pinned in assets/model-metadata.json after final integration. Native/exported reports and bounded viewer checks are listed in QA-STATUS.md. Current browser scope is separately listed in browser-qa/browser-review.json. Historical Fa browser acceptance is not inherited. Standalone file-route execution, physical devices and performance require separate verification.