Variable MOBILE_NAVIGATION_SOURCESConst

How the app reached a screen, by meaning only: cold_start (first screen of an app start), warm_start (brought back from background), button (an in-app action), tab (a bottom-bar switch — which tab is the screen the switch reaches), search_result (a SERP, or a profile opened from it), inbox (a DM thread opened from the inbox list), inbox_new_message (a DM thread entered from the "New message" compose flow — the group creation's thread, Android 451 direct-new-group chain direct_thread:5:inbox_new_message), suggested_users (a profile opened from the suggested-users row of a profile, Android 451) and third_party_url (a reel opened from a link outside the app). The wire spelling is the platform's: Android writes main_direct for a switch to the Direct tab, iOS main_direct_inbox, and an iOS screen pushed over another carries an empty source; every platform maps these meanings in its own catalog.