@Examine this file for examples of embedded control codes.
This line should be transmitted as code at normal speed.+
@ This line should not be displayed or sent, note <space> at start.
@Get ready for a speed change to 10 W.P.M.

@10
This line should be transmitted at 10 W.P.M.+
@Speed change to 15 W.P.M.

@15
@Speed change remains after this file finishes.
vvv vvv vvv+*