Branding
Branding refers to the burning of a mark into the skin of humans or animals. The term comes from livestock farming, where a brand was used to identify ownership. In BDSM contexts, the term is sometimes used for permanent markings or symbolic acts intended to signal belonging.
Branding is a highly risky, irreversible practice. It causes real burns or cold injuries and can leave lifelong scars, infections, loss of sensation, and other permanent consequences. Such acts are not to be understood as play and should not be performed without medical necessity or professional involvement.
In long-term BDSM relationships, branding is sometimes mentioned as an expression of attachment or ownership fantasy, but from a factual point of view real burn wounds require medical treatment. Any form of self-inflicted or improvised skin injury is strongly discouraged. The liquid-nitrogen application mentioned in the source text is not branding in the strict sense; it would also constitute severe and dangerous tissue damage.