Left Square Bracket Upper Corner ⎡

⎡ (U+23A1) is a standard Unicode character that you can copy and paste anywhere text is accepted. This page provides a concise reference with safe tips, internal links, and practical guidance so you can use it reliably across apps and platforms.

What it is and where it’s used: Left Square Bracket Upper Corner is part of the Symbols family (block: Miscellaneous Technical). If you need styled or decorative alternatives, try our Fancy Text tool to generate compatible text that works in most modern interfaces.

History & usage: The character with codepoint U+23A1 is the LEFT SQUARE BRACKET UPPER CORNER. It sits in the Miscellaneous Technical block and belongs to the Common script. In history, this symbol appears in technical texts and early typesetting to mark the start of a cornered bracket. In modern use, it functions as a bracket to group items, parameters, or quoted text in writing and code. People place it at the top left corner of a bracket pair to visually show nesting or to open a list. It helps programmers and writers separate parts of an expression without closing the line. The symbol is used together with other square brackets to form boundaries around data, options, or strings. It is not a standard punctuation in everyday prose, but in technical and mathematical materials it helps clarity. The character is part of Unicode, which catalogs symbols for consistent use across devices. When you see it, you understand it marks a starting point. It keeps code and documents tidy and readable.

Copy and input: the quickest method is to copy the character here. You can also insert it by its codepoint U+23A1 in many development tools or editors. Some operating systems provide a character viewer or input palette that lets you search by name or code and insert the glyph into documents.

Display and fallback: if you see an empty box (tofu) or a placeholder rectangle, the active font might not include this codepoint. Switching to a font with broader Unicode coverage or using a fallback font usually fixes the issue. On the web, ensure the page’s font stack includes a general‑purpose fallback.

Related references: browse the Categories for similar characters. When choosing a symbol, prefer the official codepoint for semantic clarity and better compatibility with search, copy, and accessibility tooling.

See our category page for related symbols.