GNU Emacs

13.3 Saving Rectangles in Registers

A register can contain a rectangle instead of linear text. See Rectangles, for basic information on how to specify a rectangle in the buffer.

C-x r r r

Copy the region-rectangle into register r ( copy-rectangle-to-register). With prefix argument, delete it as well.

C-x r i r

Insert the rectangle stored in register r (if it contains a rectangle) ( insert-register).

The C-x r i r ( insert-register) command, previously documented in Saving Text in Registers, inserts a rectangle rather than a text string, if the register contains a rectangle.