Some of these folders include:
You should avoid saving to folders that are not normally visible in the Finder because it may make locating the file more difficult later. Additionally, the file may later be deleted or moved to the Trash by Mac OS if saved into some of these folders.
It is up to each application to properly specify what kinds of folders and files should be listed in Open/Save dialogs. Please consult with the application vendor if you believe a folder or file is displayed in error.