# Sub-Banners: Overview

## Description

The TWL launcher displays application banners, but also displays separate banners, called "sub-banners," in addition to those specified in ROM specification file.
A NAND application can overwrite sub-banners, which makes it possible to implement a banner image that changes as the game progresses. However, you cannot change the game title in the banner.

The launcher will give priority to a sub-banner and display it, if it exists. Otherwise, it will display the normal banner. This has the same behavior in the software management screen in system settings. Because a sub-banner is a NAND file, once set, it will be saved in that state, even if the power is turned off, and always be displayed unless it is unset.

For information on creating sub-banner files, see Banner: Overview. You can create a sub-banner file by specifying the `-s` option to `makebanner.TWL`.

Sub-banners can only be used by NAND applications. They cannot be used by card applications.

## Implementation in Applications

Sub-banners can be used if `TRUE` is specified for `SubBannerFile` of the RSF file in the ROM specification file.

>        #  ROM SPEC FILE

>     AppendProperty
>     {
>         ....
>         #
>         # Enable SubBannerFile
>         SubBannerFile    TRUE
>     }

Use `NA_SaveSubBanner` to display a sub-banner. If `NA_SaveSubBanner` is successful, a sub-banner will be displayed thereafter. Use `NA_DeleteSubBanner`, on the other hand, to hide a sub-banner.

You can dynamically create sub-banners in a program. Edit the `anime` member of the `NASubBanner` structure. Use `NA_MakeSubBannerHeader` to set the `header` member. See `NASubBanner` for information on the sub-banner structure.

Use `NA_LoadSubBanner` to get the sub-banner that is currently set.

## See Also

NA Function List: Sub-Banners
NAND Application Sample Demo
Banner: Overview

## Revision History

2008/10/30 Mentioned that this can be overwritten by NAND applications.
2008/09/26 Added information about the software management screen.
2008/09/25 Added links to the ROM specification file and Banner: Overview.
2008/09/16 Initial version.

CONFIDENTIAL