.cc;The Title of the Document Should Be Centered

.pp;The first paragraph begins here with a five-space indentation from the left margin which the machine instructs the line-printer to execute based on a "macro" pre-defined within the source code for Waterloo Script.  The users also could define their own macros, but most ordinary users stuck to the pre-defined limits.  All of this text would be printed as belonging to the paragraph because the computer would not encounter a period in the left margin unless a pre-defined command instruction followed it

.us;like this

which would create an underscored like this within the paragraph but no line break because the ".us" instruction did not tell the machine to skip a line.

.pp;Time for a new paragraph, machine!  We're almost done.  But first, let's indent a block quote five spaces:

.in 5;The contents of the block quote would keep being formatted five spaces from the left margin of the main text until the "indent" instruction was turned off.

.in 0;This is one way to do that.  Another is

.in off;The machine would ignore this one since it had no "indent" command in its memory.  Time to end this document.