TagID

Tagid is a term used across multiple domains to refer to an identifier assigned to a tag within a system. It is not a single standardized specification, but rather a conventional name for a field or property that stores the identifier of a tag or tag-like element. In many codebases tag IDs appear as a dedicated field such as tag_id, or as a property named tagId, depending on the programming language and naming conventions.

In markup languages, the closest formal concept is the id attribute. In HTML and SVG, an element’s id provides a unique identifier within the document and enables direct manipulation by CSS selectors and JavaScript, such as selecting an element with a specific id or linking to it via a fragment identifier. In XML, IDs are defined within a document type definition or schema and are expected to be unique, supporting identity references between elements.

In tagging systems and data models, a tag’s identifier commonly serves as the primary key for the tag entity. Tag IDs are used to link content items to tags, support efficient lookups, and enable relationships in relational databases or graph structures. They are typically numeric integers or universally unique identifiers (UUIDs), chosen for stability and portability.

Best practices for tag IDs include ensuring uniqueness, using stable and descriptive identifiers, and adhering to project naming conventions (such as lowerCamelCase or snake_case). Avoid changing tag IDs once assigned, and consider how IDs are exposed in APIs to balance usability and security. See also: HTML id attribute, DOM, CSS selectors, databases, tagging systems.