All subject headings for bridges have been changed from indirect to direct order. See CSB #23
In case you are wondering why I do these changes one at a time, it is because I think the work involved to update a database is more manageable when approached a little bit at a time.
Some examples of changed bridge headings:
Bridges, Arched is now Arch bridges
Bridges, Cantilever is now Cantilever bridges
Bridges, Concrete is now Concrete bridges
You get the picture…