3.5.5.4 Create Backups

If this option is checked, the editor will create a backup file named the same as the original but with '.bak' appended to it the first time the file is saved in each edit session. Note that it is not created with each save, but only the first!

Also note that appending the '.bak' extension is meant literally - unlike editors that hail from the old 8.3 filename era, which would remove the old extension and replace it with .bak (e.g. 'foo.pov' would become 'foo.bak'), we literally append '.bak', such that 'foo.pov' becomes 'foo.pov.bak', thus avoiding the problem that having two files named 'foo.pov' and 'foo.inc' in the same directory would have caused.