The term sauwastika (or sauvastika) (as a character: 卍) is sometimes used to distinguish the left-facing from the right-facing swastika symbol, a meaning which developed in 19th century scholarship.
The left-facing variant is favoured in Bön and Gurung Dharma; it is called yungdrung in Bon and Gurung Yantra in Gurung Dharma. Both the right-facing and left-facing variants are employed in Hinduism and Buddhism; however, the left-facing is more commonly used in Buddhism than Hinduism and the right-facing is more commonly used in Hinduism than Buddhism.
In Buddhism the left-facing sauwastika imprinted on the chest, feet, palms of Buddha and also the first of the 65 auspicious symbols on the footprint of the Buddha. In Hinduism the left-facing sauwastika is associated with esoteric tantric practices and often stands for Goddess Kali.
Sanskrit sauvastika is the vṛddhi of svastika, attested as an adjective meaning "benedictive, salutatory". The connection to a "reversed" svastika is probably first made by Eugène Burnouf in 1852, and taken up by Schliemann in Ilios (1880), based on a letter from Max Müller, who is in turn quoting Burnouf. The term sauwastika is used in the sense of "backwards swastika" by Eugène Goblet d'Alviella (1894): "In India it [the gammadion] bears the name of swastika, when its arms are bent towards the right, and sauwastika when they are turned in the other direction."
The term has been misspelled as suavastika, a term attributed to Max Müller by Wilson (1896). Wilson finds that "The 'suavastika' which Max Müller names and believes was applied to the swastika sign, with the ends bent to the left [...] seems not to be reported with that meaning by any other author except Burnouf."
Eugene Burnouf, the first Western expert on Buddhism, stated in his book Lotus de la bonne loi (1852) that the sauvastika was a Buddhist variant of the svastika.