The specifications

Here is a collection of the RFCs for the various parts and components of QUIC and HTTP/3.

Version Negotiation

Compatible Version Negotiation for QUIC

Transport

QUIC: A UDP-Based Multiplexed and Secure Transport

Recovery

QUIC Loss Detection and Congestion Control

TLS

Using TLS to Secure QUIC

HTTP

Hypertext Transfer Protocol Version 3 (HTTP/3)

QPACK

QPACK: Header Compression for HTTP/3