Extension options (Name Pages tool)
Use these options in the Name Pages and Name Pages On Background tools to enter a name extension for all page names. The extension (if any) is incremented per page and appended to the base name.
If you leave the name extension blank, all pages in the selected range (or on the selected background) are named the identical base name.
If you enter an extension, pages are named uniquely by incrementing the extension and appending it to the base name. Check the Put Space option to add a space between the base name and the extension.
If the base name is scriptPage, the extension is 1, and you check the Put Space option, pages in the selected range are named: