@since

The @since tag documents the version in which an element first became available. It is the opposite number of @deprecated: where that tag marks the end of an element's life, @since marks its beginning, letting consumers check whether a given feature exists in the version they depend on.

"@since" [ <Version> ] [ <Description> ]

Parsing a @since tag produces a SinceTag instance exposing $version — the version at which the element became available, or null when none was given — alongside the inherited $description. It shares this shape with @deprecated and @version.

abstract class VersionedTag extends Tag
{
    public function __construct(
        string $name,
        public readonly ?string $version = null,
        ?DescriptionInterface $description = null,
    ) {
        parent::__construct($name, $description);
    }
}

final class SinceTag extends VersionedTag {}

Defined by the PSR-19 draft @since proposal and phpDocumentor's own @since reference.

05 July 2026