If an invalid selection is chosen 3 times in a row, the user is connected to the youngest session.
By default, if only one session exists, the user is connected to that session, and if no sessions exist, a new session is created -- such that there is no interactive prompt in the normal behavior. However, some users may choose to always be prompted, by touching the file $BYOBU_CONFIG_DIR/.always-select.
Note that BYOBU_CONFIG_DIR=$HOME/.byobu.
Named sessions that begin with a "." are "hidden" from byobu-select-session(1). This is useful, for instance, if you do not want a session to be automatically selected at login. Example:
byobu -S .hidden
The complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL on Debian/Ubuntu systems, or in /usr/share/doc/fedora-release-*/GPL on Fedora systems, or on the web at http://www.gnu.org/licenses/gpl.txt.