noun
lenticular bracket
A typographical symbol shaped like a bracket with a small corner or notch, used for emphasis or decoration in Japanese text. 【】 is listed as an example.
隅付き括弧は、強調したい語句を囲むのに使われることがある。
Lenticular brackets are sometimes used to enclose words or phrases you want to emphasize.
Compound of 隅 (corner) + 付き (attached, with) + 括弧 (bracket). The name describes the bracket's distinctive cornered shape.