META Resources
Standards: IPTC-IIM
Based on a format for text files that described accompanying media, the IPTC’s Information Interchange Model launched in 1991, providing a new way to handle “digital resources” with metadata and content held in a binary-structured framework. In the mid-1990s, Adobe added the ability to insert descriptive metadata in TIFF and JPEG digital image files, giving birth to IPTC headers. An Adobe-specific container or “wrapper,” dubbed the Image Resource Block (IRB), encapsulated a subset of the IPTC’s IIM metadata structure, allowing editing through the Photoshop "File Info" dialog.
Many third-party developers have created software applications that read and write to IPTC headers. But some consider it metadata “black art,” since the storage location and structure vary with image file formats. Occasional glitches appear in how certain diacritical characters - such as accents, tildes, umlauts, etc. (áçèîñõü) - translate when exchanging files between operating systems. This schema also has specific limits on the number of characters each field can hold.
For specifics on the various field names used in different imaging applications, you might want to download the IPTC Core mapping chart on the Controlled Vocabulary website
IPTC Official Website: http://www.iptc.org/
