Lower a space (align). Delete one or more letters (delete). Turn the nick (turn over). Align vertically. Indentations (new paragraph). Invert the words (put after). Add space (widen). Change letter (misprint). Join horizontally (reduce space between lines). Detach horizontally (increase space between lines). Join vertically (squeeze). Detach vertically (space). Remove and join (bring closer). Compare with original (meaning there is a doubt). Correction not to be made (valid). Put the composition afterwards. Clean the dirty ones. Exponent letters and descending apostrophes. Turn the page (continue on next page). Various signs used to indicate ruined letters, misprints, etc. They have different shapes to easily distinguish between errors and avoid confusion.