It seems that the /enchant command limits the minimum enchantment id to 1 instead of 0, which prevents enchanting with the Protection enchantment.
Linked issues
is duplicated by 3
Comments 15
Negative values are too small.
Maximum value: 255
Float values don't work
Double values don't work
Hexadecimal values don't work
Also, numbers must match an enchantment ID. (http://www.minecraftwiki.net/wiki/Enchanting#Enchantments)
Currently, I'm not at home. Could someone test to see if any of these also fails?
Negative values.
Float values.
Double values.
Hexidecimal values.
I would love to test if letters would be valid or not, but seems like going above 32 is unlikely able to cause an error. It would also seemed that someone else had tested for large positive values, and they don't work. All is good.