Data that is more free-form, such as multimedia files, images, sound files, or unstructured text. Unstructured data does not necessarily follow any format or hierarchical sequence, nor does it follow any relational rules. Unstructured data refers to masses of (usually) computerized information which do not have a data structure which is easily readable by a machine. Examples of unstructured data may include audio, video and unstructured text such as the body of an email or word processor document.

An identifier for an object which is guaranteed to be different from identifiers of all other objects in a collection. Within a database, every object will have a UID that is unique within the database. A UID assigned by a central registry (such as an ISBN for books, or a DOI for data) will be unique for all objects for which it is assigned.

The Unicode Standard is a character coding system designed to support the worldwide interchange, processing, and display of the written texts of the diverse languages and technical disciplines of the modern world. In addition, it supports classical and historical texts of many written languages. The Unicode Standard provides a unique number for every character, no matter what platform, device, application or language.

A meeting, similar to a conference, but with no agenda fixed in advance. Using various established techniques, participants jointly agree on the day what sessions will run. Some more traditional conference sessions with invited speakers may also be included. A popular format among the tech community, an unconference can be combined with or run alongside a hackathon based on open data.

A simple text format for a database table. Each record in the table is one line of the text file. Each field value of a record is separated from the next by a tab stop character. It is a form of the more general delimiter-separated values format.

Source: US OD

The ‘triples’ of RDF data can be stored in a specialised database, called a triple store, against which queries can be made in the query language SPARQL.

Source: ODH

Public transport routes, timetables and real time data are valuable but difficult candidates for open data. Even when they are published, data from different transit authorities and companies may not be available in compatible formats, making it difficult for third parties to provide integrated transport information.

A principle of the public administration and democratic political system. Governments and other public sector bodies are said to be transparent when their workings and decision-making processes are well-understood, properly documented and open to scrutiny. Transparency is one of the aspects of open government. An increase in transparency is one of the benefits of open data.

Tab-separated values (TSV) are a very common form of text file format for sharing tabular data. The format is extremely simple and highly machine-readable.

Source: ODH

All data has some structure, but ‘structured data’ refers to data where the structural relation between elements is explicit in the way the data is stored on a computer disk. XML and JSON are common formats that allow many types of structure to be represented. The internal representation of, for example, word-processing documents or PDF documents reflects the positioning of entities on the page, not their logical structure, which is correspondingly difficult or impossible to extract automatically.