Tagvalue

Tagvalue is a concept in information management describing a simple metadata unit composed of a tag and its value. The tag is a label or key that names the metadata field, while the value is the data associated with that field. Tagvalue pairs are used to annotate a wide range of digital objects, including documents, images, datasets, and software configurations, enabling search, filtering, and automated processing.

Formats: Tagvalue data is often serialized as plain text lines in the form tag=value or tag: value. This pattern underpins common configuration files and environment files, and appears in many data-interchange formats when representing simple metadata.

Data structures: In programming, a collection of tagvalue pairs is typically stored as a map, dictionary, or associative array, allowing fast lookup by tag.

Applications: Metadata tagging for media libraries, document management, data catalogs, logging, and provenance tracking. Tagvalue metadata supports lightweight schemas, human readability, and portable exchange.

Limitations: Tagvalue systems may face ambiguity when the same tag is used with different meanings (homonyms), or when values require structured formatting. Without a formal schema, validation can be limited, and multi-valued or hierarchical metadata may require conventions or nested structures.

See also:

- Key-value store

- Metadata

- Configuration file

- Tagging

- JSON

- YAML