What does the T in USDT stand for?

I'm curious to know, in the context of cryptocurrency, what does the letter "T" stand for in the abbreviation "USDT"? Is it referring to a specific term or concept related to the digital asset, or is it simply a placeholder for a certain characteristic or feature of the coin? As a professional in the field of cryptocurrency and finance, I'm eager to gain a deeper understanding of the terminology and conventions used within this rapidly evolving industry.