These descriptions provide information about file formats, file-format classes, bitstream structures and encodings, and the mechanisms used to compress files or bitstreams. Inclusion of a format does not imply that it is preferred or acceptable for Library of Congress collections. Conversely, omission of a format from the list does not imply that it is not preferred or acceptable. Descriptions will be drafted and added over time. Persons with specialized knowledge are encouraged to review and comment on the descriptions using this contact form