(1) For topic identifiers, see
hashtag.
(2) For physical object identification, see
RFID tag.
(3) For word recognition, see
smart tags.
(4) For text-based codes, see
XML,
tagged text,
HTML tag,
character tag and
paragraph tag.
(5) To "tag someone" means to notify or mention another person on social media.
(6) For Apple's Bluetooth tracker, see
AirTag.
(7) A set of bits or characters that identifies a file and its content, which is often found in the header of such files. This type of tag generally occupies predefined locations in the header rather than embedded throughout the file.
(8) A name (label, mnemonic) assigned to a data structure, such as a field or record. See
XML document.
(9) A descriptive field in a music or video file. See
ID3 tag.
(10) A field that identifies the contents of a data record. See
key field.
(11) A brass pin on a terminal block that is connected to a wire by soldering or wire wrapping.