.APF File Extension

Certificate file used by Adobe Acrobat as well as other Adobe programs; contains a digital certificate that is used to authorize and identify a source of information.

APF files are Adobe's legacy certificate format and have not been used after Acrobat 5. They can be upgraded in Acrobat to a newer certificate format.

Driver file used within the firmware of Sony Ericsson mobile devices; contains data for acoustic settings, such as sound quality and the speaker and headphone volume; used for "modding" a Sony Ericsson device.

APF files can be found in the ifs\settings\acoustic\ directory on Sony Ericsson mobile devices.