Calculator Text Format
A format which is both human and computer readable for creating casio calculator BASIC programs which can be displayed on the web for people to read and type into calculator or transfer it using software for those programs which are longer than you would want to type.
These ctf specifications pages taken from Tom Wheeley's Site which is now archived at the wayback machine:
wayback machine
The program Casform can be used to convert txt and ctf into other formats.