The most common packets, in terms of overall number transferred, are T packets carrying the data for a file transfer. These packets have no further semantic value and are formatted as described above. The T packets also include "subtypes", Tr for "transfer resume", TF for "transfer failure" if the resume did not match the partially downloaded file, and TI for "transfer information", which sent details on the file being transferred. Most protocols would send file information as a special "zeroth packet" in the transfer stream itself, whereas in B Plus this was handled by a separate packet type and effectively out of the transfer stream itself, although there was no real difference in practice.