Sigils
The modern method of compressing a written desire into an abstract glyph and forgetting it was set out by one English artist in 1913, later systematised into a full magical system by another in 1978. Both drew on an older tradition of drawn ritual signs, including demon-summoning seals and Hindu tantric diagrams.
Austin Osman Spare, The Book of Pleasure (1913); Peter Carroll, Liber Null (1978)
Abstract symbols created to represent and activate a specific desire or intention, now the single most widely practised technique in contemporary occultism.