This is more or less a continuation of what started in forum #16424, but I've kind of expanded beyond just the school_bag tag.
In the attempt to define school_bag, I've found that it is necessary that we need to define/redefine satchel, shoulder_bag, and messenger_bag.
First off are the easy ones.
I'd like to define shoulder_bag as "a bag that lacks handles and is intended to be carried with a single shoulder strap."
Following that, messenger_bag should be defined as something like "a type of shoulder bag with a shoulder strap that is worn across the body and has a large flap."
Neither of these definitions will really impact the current image population tagged with these tags. Though the definitions would suggest a messenger_bag -> shoulder_bag implication.
The hard one is satchel. There are currently 140 images tagged with this tag, but there are several problems with this tag. The images depicted completely overlap with the images tagged school_bag, the definition itself leads this tag to overlap with school_bag, and finally the images tagged satchel don't really follow any real definition of satchel that I could find.
I'd like to redefine this tag with a Frankenstein's monster of a definition composed from several handbag glossaries and a luggage glossary. The new definition I'd like to give it is "a soft flat bottomed bag with two handles or straps and a zipper or clasp opening at the top."
The disadvantage of this new definition is it will require the complete gutting of the tag, as right now there is probably not a single image under the tag that would go by this definition. On the other hand, the advantages are it does away with overlap with school_bag, gives it a specific definition, and gives a tag to the newer style of school bags being used (ex: post #406930, post #189816, post #405677).
Finally this all leads up to how to define the school_bag tag. As it currently stands, this tag is predominately used on images depicting the older style of book bag used by middle and high school students, which I believe is best described as a flap over briefcase. This tag though has also been used to tag a variety of other school bags, the most common of which would fall under the new definition of satchel and randoseru.
While I do believe the "flap over briefcase" style of school_bags could deserve its own tag, I believe more that the school_bag tag should be broadened out in definition to include the other style of bags (ie new satchel, shoulder_bag, and messenger_bag). There are right now 21 pages of images under school_uniform bag -school_bag, many of which are non-briefcase styles of bags used by students. So pretty much I think school_bag should be defined to be any book bag used by Japanese middle and high school students.
If we're to give the flap over briefcase style school bag its own tag, I think something like traditional_school_bag or something would work better than hogging the more general sounding school_bag tag.
Updated by juunigatsu no usagi