The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/14/continuous-archiving.html
Description:
Chapter 26.3.2. "Making a Base Backup" states that "To make use of the
backup, you will need to keep all the WAL segment files generated during and
after the file system backup. To aid you in doing this, the base backup
process creates a backup history file that is immediately stored into the
WAL archive area. This file is named after the first WAL segment file that
you need for the file system backup. For example, if the starting WAL file
is 0000000100001234000055CD the backup history file will be named something
like 0000000100001234000055CD.007C9330.backup."
In my experience with pg_basebackup with tar format (-Ft) no backup history
file was produced. Instead I found first WAL segment name in "backup_label"
file inside of "base.tar" archive.