II file format is used by IconWorkshop as extended file information file. This file is generated and stored separately from the main icon file.

The IconWorkshop Extended Information file is used to store the metadata information and details that are associated with a specific file. This metadata is stored along with the main vector based image. The data stored in metadata includes title, author name, description and date. These files are usually used for indexing purposes and hence are used by IconWorkshop librarian. After the image file is completed the metadata information is set to hidden and the file name is set to corresponding image file name.