Hi Rick,
Interesting questions.
"moodle2" stands for Moodle 2.x type of backup, opposed to the 1.x way it was done...
As explained in the course backup documentation, the backup name can also end with -nu (no user) or -an (anonymized names).
And for me, with french language used, the "backup" (at the beginning) is replaced by "sauvegarde".
But it doesn't seem to be possible to personnalise the name as you want easily.
Séverin