It's probably a default ordering or an ordering by an unshown database ID value. It's a small enough set that it doesn't really matter for practical purposes, but I guess it does betray a lack of attention to detail.
Is 8 before or after 4 in the alphabet?
If it were ordered by ordinal values, "/" is 47 and " " is 32, so "1 in" would come before "1/2 in".
It's not alphabetized by letter word. Because while "Eight" comes before "Four", "Specialty" would come before "Three".
No matter which way you attempt to order it, something is out of order.
Softtalker probably got it right. This is some default or id sort.