The best places to start learning about T visas are as follows: 

• The USCIS Policy Manual sections on T nonimmigrant status, Vol. 3, Part B, and on waivers for T applicants, Vol. 9, Part O (both first released in October 2021).
• The T visa regulations are located at 8 CFR § 214.11. The regulations provide guidelines on the eligibility and evidentiary requirements.
• The Preamble to the 2016 interim regulations, which provides useful background and context to help interpret the regulations.
• The T visa statute, INA § 101(a)(15)(T), which lays out the statutory requirements.
• The I-914 Instructions on USCIS's webpage. The instructions include some general information on the eligibility requirements and a list of initial evidence.

We also recommend reviewing our free T visa resources here: https://casttta.nationbuilder.com/t_visa_intro. On this page, you will find a complete list of our advisories, e-learning courses, and webinars.