In the following dialog which I get when running a Centennial app,
what does "do not show this dialog again" mean?
Don't show and don't build
Or
Don't show and do build
When you have "Do not show this dialog again" checked, it remembers the choice you make.
If you press Yes while the check box is checked, it will be
Don't show and do build
If you press No while the check box is checked, it will be
Don't show and don't build
The setting that is changed based on your choice is located in the Tools->Options menu.
Go to the "Projects and Solutions" group, and choose the "Build and Run" page.
The first dropdown box, "On Run, when projects are out of date", will show what action is taken when you try to run when projects are out of date.
"Prompt to build" will show the dialog in your question. The other two options are self-explanatory, Always or Never build.
An extra note, if you press Cancel on the dialog, then nothing is done. No settings are changed, no build is started, and the out of date project output is not launched. It's like the dialog never opened in the first place.