Identical to Plus Combining Reverse Solidus Overlay HTML entity &bnequiv;

&bnequiv;: HTML entity for Identical to Plus Combining Reverse Solidus Overlay ≡⃥ (U+2261 U+20E5), with decimal, hex, CSS, JavaScript and URL codes.

Entity: &bnequiv;
Code points: U+2261 U+20E5
Unicode name: IDENTICAL TO + COMBINING REVERSE SOLIDUS OVERLAY
Block: Mathematical Operators
Category: Math symbol (Sm)
Since: Unicode 1.1
Defined in: HTML5

Codes to copy

HTML named	`&bnequiv;`Works in HTML; in XML only & < > " ' are predefined.
HTML decimal	`≡⃥`Works in HTML and XML.
HTML hex	`≡⃥`Works in HTML and XML.
CSS	`content: "\2261 \20E5";`In a stylesheet, for ::before and ::after.
JavaScript	`"\u2261\u20E5"`Also valid in JSON.
Python	`"\u2261\u20e5"`Python 3 string literal.
URL	`%E2%89%A1%E2%83%A5`Percent-encoded UTF-8 bytes, for a path or query value.
UTF-8 bytes	`E2 89 A1 E2 83 A5`6 bytes in all.
UTF-16	`2261 20E5`2 code units, which is what JavaScript length counts.

When to use it

&bnequiv; writes a sequence of 2 code points (U+2261 U+20E5) that together show as one symbol. Specialist notation like this usually belongs in MathML, which positions it correctly; the entity is for occasional use in running text.

The name comes from the HTML5 list (much of it shared with MathML), so it works in every current browser but not in XML or XHTML served as XML, where the numeric reference is the safe choice.

More advanced maths and arrows

All advanced maths and arrows · Every HTML entity · Encode or decode text

Source: the WHATWG HTML Standard list of named character references and the Unicode Character Database (Unicode 18.0).