The version of the base official YouTube App (v18.09) that these tweaks were injected into. Key Features & Functionality
Completely removes all forms of advertising, including mid-roll and home-feed ads. 2.2.3_YTK _DEMC_AB_iSB_RYD_YouMute_YTUHD_18.09....
The string is a shorthand used by the sideloading community to list every modification included in that specific "all-in-one" app bundle. The version of the base official YouTube App (v18