Question regarding Protection Diodes in Power Supply Project

Please see attachments.

I found a beginner power supply project online (first image). In it the author shows protection diodes attached from output to input of the regulators. The second image is a capture from the regulator mfg datasheet which shows the same diodes already mentioned as well as two others connected from the adjustment leg to the regulator outputs.

Since this is a refresher for me while I return to the world of electronics , my question is whether the extra two diodes the project author didn't include are really necessary or not? His pcb pattern for the project only accommodates the two he included in his schematic but I figure it would be easy enough to add the other two in.

Suggestions please?

Thanks for your help in advance.

Protecting diodes are necessary if load discharges slower than filter capacitor after the rectifier. Regulator must not be reverse polarized.
If the regulator is a supplying a known load you can determine if the diodes are necessary. But if you build stand allone power supply and the loads can be of any type you must place protection diodes.

The text in the datasheet says with the low capacitance and output voltage of your project then a protection diode isn't necessary for the ADJ terminal:

Oopps! I read the whole sheet but missed that part somehow? Thanks.