An .erf file (Toolset export and import) is an ERF file with the extension .erf. This file contains resources that were exported from, and can be imported into, a module via the Toolset. As such, this type of file is the primary method of transferring resources from one module to another. Aside from a few standard files found in the texturepacks subdirectory, players—including hosts—have no need of .erf files. These files are exclusively for builders. (However, it is possible for something available as an .erf for builders to be also available as an override for players.)