A short web article by Ralph Griswold introducing a notation for transforming the lines (rows and columns) of a pattern. It defines basic operations (no operation, complementation, reversal, shifts), operation sequences, combined operations in braces, permutations, defined operations, shift modes, state saving and restoring, and repeat controls, and ends with a summary table of the symbols. It is Part 1 of a series; examples are promised in the next article.