Open Document Architecture
The Open Document Architecture (ODA) and interchange format (informally referred to as just ODA) is a free and open international standard document file format maintained by the ITU-T to replace all proprietary document file formats. ODA is detailed in the standards documents CCITT T.411-T.424, which is equivalent to ISO/IEC 8613.
Source: Wikipedia — Open Document Architecture (CC BY-SA 4.0)