TDCC

Turbo-DCC (Direct Client Connection). A transfer protocol used by IRC clients. Supposedly up to three times faster than regular DCC, although, if you use DCC send-ahead, the difference is little, if there at all.

Most popular (and non-popular) IRC clients support TDCC, with the exception of mIRC.

A description of the TDCC protocol, for all you aspiring IRC client authors:

Send the victim -- er, receiver -- a CTCP "DCC TSEND <filename> <encoded-ip> <port> <filesize>". Surround the filename with quotes if it contains spaces. Open a listening socket on the given port. When the receiver connects, send the data as fast as your TCP/IP stack will allow -- don't wait for acknowledgements, as TDCC doesn't use them. The receiver will close the connection after it has received the entire file.

TDCC is an exceptionally simple IRC file server method (presumably standing for Trivial DCC). In a TDCC server, typing the trigger immediately initiates a file send. Unlike XDCC or fserve there are no file listings or chat windows, simply a send. As such, this kind of server is usually used for serving single extremely small files, such as a text file containing the channel rules (typically on the trigger "!rules"). Most decent IRC script packages such as UPP or Sysreset include a TDCC function.