The Table of Contents is the central unifying index of a DBDOC project file. Until DBDOC 11.1, the "Classic" text view table of contents listed every document in the project, in a grand (and sometimes very long) list. Although there was a certain elegance of simplicity to this presentation, when the index became tens or hundreds of pages long, its utility was somewhat compromised.
The Treeview Table of Contents was developed in response to the shortcomings of the Classic toc. It presents a sensible hierarchical view of the project contents, and has served well. Minor shortcomings have included the fact that it is not directly searchable, and not every index visible in Classic form can in fact be viewed view the Treeview. Internally, of course, it also required separate maintenance.
In DBDOC 11.1, we have bitten the bullet and merged the Classic and Treeview table of contents in . The new table of contents is hierarchical -- just like in Treeview TOC, you see the chapter headings at the top level, but instead of a tree, you simply click to display appropriate sub-indexes.