When you execute the Compile Solution to Single Documentation operation, you will generate a single documentation for multiple projects. The projects may have different properties and therefore we need to specify some common properties that will be used in this case. There are some essential settings that must be common, such as output format (template), output path, help title, custom topics and file naming. Other settings such as footer text, regex filters may be taken whether from individual projects or, again, from common properties. The common global properties are called solution-wide properties. They are part of the solution profiles stored in SOLUTION_NAME.sln.vsdoc file. Each solution profile has it's own solution-wide properties.
The solution-wide properties can be edited the same way as project properties. Click on the project name to show the list of available projects.
Select SOLUTION-WIDE PROPERTIES. Now you can edit the common properties. The window is highlighted by green color. The Compile button is disabled because there is no active project selected. If you wish to compile documentation for any project, make that project active by selecting it at the top.
So when you execute the Compile Solution to Single Documentation operation, you can select which common properties will be applied to the entire documentation and to each of its topics.
The selected common properties will override the properties from individual projects. For example, if you select to override the page footer text, the common footer will be generated in all topics. Otherwise, the topics belonging to a particular project will have a footer defined in that project. That means that various topics inside the same documentation will have different footer texts.