タグ
たぐ
noun
tag, label
1.
tag, label
A label or marker attached to an item for identification or information. Includes physical tags (clothing labels, price tags) and digital tags (hashtags, HTML tags, metadata tags).
Usage
タグ covers both physical labels (clothing tags, price tags, luggage tags) and digital tags (hashtags, HTML tags, metadata labels). ハッシュタグ (hashtag) is the most common digital use.
タグ付け means "tagging" (applying tags to items or posts).