General RCS Info from pocket-lint.com
Some good general information here: https://www.pocket-lint.com/phones/news/144258-what-is-rcs-messaging-the-messaging-format-set-to-take-over-your-android-phone
Some good general information here: https://www.pocket-lint.com/phones/news/144258-what-is-rcs-messaging-the-messaging-format-set-to-take-over-your-android-phone