I.3 Saving Rectangles in Registers

A register can contain a rectangle instead of linear text. The rectangle is represented as a list of strings. See section H.10 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 numeric 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 command inserts a text string if the register contains one, and inserts a rectangle if the register contains one.

See also the command sort-columns, which you can think of as sorting a rectangle. See section AC.21 Sorting Text.