You use this dialog box when you Create a Bloom Collection.
It functions as wizard, with a series of panes where you type or choose information to distinguish the collection. Each pane has a Next button to move you to the next pane. The last pane has a Finish button.
If necessary, you can click the down arrow near the top-right corner of the dialog box and choose a different User Interface language so you can read the words in each pane in that language.
Dialects of a particular language can be handled as separate collections.
In the Create New Bloom Collection dialog box, choose the main language for the collection. Then, type the name of a dialect in the box that has this label:
Display this language this way
Once you have created a collection for each of the dialects, use the Other Collection button to open a collection. You can translate or make books in each collection. Internally, all of your books will use the same language code, but when you are editing in Bloom it will show the name of the dialect.