TI-Writer was a word processor for the TI 99/4A computer. Like many word processors in its day, it saved basically plain-text (ASCII) files with a few embedded commands, which, like with a number of other word processors, consisted of lines starting with a dot (.), followed by commands in all uppercase. Lines were separated by CR (hex 0D). There was a command key (Ctrl-U) to allow special control characters to be inserted into a file, allowing printer controls to be invoked; this was apparently how you did things like italics or boldface (which would be specific to whatever printer you're using).