Don't be cruel, if for no other reason than to not be cruel to people with stutters or other speech challenges, use the initialism TRPG not TTRPG. Additionally for consistency of documentation and professional language efficiency. All of RPG Research's documentation, as well as the Certified Role-Playing Game Professional documentation follow this standardized approach. Until recently, it seemed pretty standard to use TRPG, but in the last few years, for some strange reason an increasing number of people are starting to use TTRPG with 2 Ts. Why?
Examples of RPG Formats according to the Hawkes-Robinson RPG Model and the interaction patterns according to the Avedon Interaction Patterns (1974).
Terminology for Role-Playing Game Formats.
As with most content by W.A. Hawkes-Robinson, this content is posted as a Request for Comments (RFC). Here is the February 20th, 2019 revision of the RPG Model draft as proposed by W.A. Hawkes-Robinson beginning in 2004, revised in 2007, 2010, 2012, 2014, 2018, & now 2019.
This is a work in progress. With so much going on you may have missed the recent broadcasts related to role-playing game theories we have been covering at RPG Research. This is a quick summary of a few of the recent topics with links to the audio/video.