int32 · default 0 · range 0 to 1

Style of the HUD subtitle background: 0 solid, 1 outline.

client

clientdll Registered by the client

archive

archive Saved to the config file

peruser

per_user Holds a separate value per split-screen user

ConVar.Find("citadel_subtitles_background_style")?.SetInt(0);
int value = ConVar.Find("citadel_subtitles_background_style")?.GetInt() ?? 0;