so, enter is CHR$ 13 (or "\r" in linux). other characters with codes below 32 are special control characters and some of them are not printable and are shown as '?'. that is how rst #10  (or BASIC PRINT) works. some of those control characters can change color of text or background, or to move cursor to different position on screen.

for example, try to run this command in basic:
PRINT CHR$ 22; CHR$ 10; CHR$ 10; CHR$ 16; CHR$ 6; CHR$ 17; CHR$ 1;"HELLO WORLD"

or create file containing characters with codes 22,10,10,16,6,17,1 and text "HELLO WORLD" and print it using .more