Metadata

Metadata is extra non-critical information about the main contents of a file, or about the circumstances in which a file was created, etc.

Many, many formats contain data that could be considered to be metadata, but this page is only concerned with dedicated metadata formats which, for one reason or another, are best documented as separate formats.

Metadata is a great thing to have for publicly-available files, but there's a sinister side to it too... it's come out lately that all sorts of people are snooping into the metadata of your life (such as who you're calling or e-mailing), and this can reveal a lot about you.

Articles about individual metadata elements are usually listed in Elements of File Formats, instead of here.

Metadata formats

 * AFCP
 * APE tag
 * DCAT-AP
 * Debian source control file
 * DESCRIPT.ION
 * Desktop Services Store (.DS_Store)
 * disc.id
 * DOS/Windows file attributes
 * EA DATA. SF
 * EPOC AIF
 * Exif
 * FILE_ID.DIZ
 * Finder information
 * freedesktop.org Desktop Entry
 * ID3
 * Internet Archive metadata
 * IPTC-IIM
 * IPTC Photo Metadata
 * Mac OS Alias
 * MakerNote
 * MEF (Metadata Exchange Format)
 * METS (Metadata Encoding & Transmission Standard)
 * MIX (Metadata for Images in XML Standard)
 * mtree
 * net.CyberCards
 * NFO
 * Nikon Sidecar (.nksc)
 * Photoshop Image Resources
 * PkgInfo
 * Portland Common Data Model
 * RDF
 * SAUCE (Standard Architecture for Universal Comment Extension)
 * SRR
 * SRS
 * Title metadata
 * Structured Data (Wikimedia)
 * Windows Shortcut
 * XMP

Metadata subcategories in other formats

 * Metadata formats related to archiving
 * Metadata formats related to audio and music
 * Metadata formats related to executables
 * Metadata formats related to graphics
 * Metadata formats related to radio or broadcasting
 * Metadata formats related to video
 * Metadata (and feed/syndication) formats related to the Web

Links

 * Anyone Brushing Off NSA Surveillance Because It's 'Just Metadata' Doesn't Know What Metadata Is
 * Metadata Equals Surveillance
 * US drones could be killing the wrong people because of metadata errors
 * Art as data as art
 * MetaPhone: The Sensitivity of Telephone Metadata
 * Misunderstanding Metadata
 * Linked Archival Metadata: A Handbook
 * Metadata: Organizing and Discovering Information (Coursera course)
 * Tupac, or 2Pac? Sadly, Music Industry Still Doesn’t Know…
 * MDQC: program to read metadata of files and compare to specs