wp-admin/includes/taxonomy.php:234$tag_nameint|stringarray|WP_Errorfunction wp_create_tag( $tag_name ) { return wp_create_term( $tag_name, 'post_tag' );}Introduced in 2.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/taxonomy.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.