Currently you can set the default prefix for forms in Administration->Settings->Advanced
Then in the settins tree:
ContentView->Controls->Forms Backend->Views->FormsBackendInsert->Sections->MainSection->Fields->Name - see the PrefixText property. We'll place this setting at a higher level and it will be easier to access (Forms->FormsTablePrefix).
Regarding the language - it will be included in the next weekly developer's build
the Telerik team
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