There are a few commands, which belong to PLAIN and not PHYZZX
which you should know about.
The basic command which allows you to tell TEX that you
would advise it that this is a good or bad place to break
a page or line of text is
penalty.
Penalties can be either positive or negative.
If a penalty is positive it tells TEX that this is not a good
place to put in a break.
The bigger the penalty is, the worse TEX thinks it is to cause
a break at this point.
The biggest allowable penalty is
penalty 10000.
If you type
penalty 10000 at a specific point in the text
than TEX, as the printer, will assume that no matter what his
judgement tells him, you insist that no break can occur at this
point.
TEX defines a control sequence
nobreak which equivalent
to typing
penalty 10000.
If the penalty is negative, then TEX is advised that you
believe this point to be a good place to cause a break.
The more negative the penalty, the better you think this place is.
If the penalty is negative and greater than
-10000, then TEX will
use its own judgement to balance off your suggestion against its
own esthetic criteria.
If the penalty is -10000 (or less), then you are telling TEX that your judgement must carry the day.
The abbreviation of
penalty -10000 is
break.
Note that using the
same commands inside paragraphs and between paragraphs
tell TEX to do different things.
Inside of a paragraph
break tells TEX to break the
current line at this point, between paragraphs it tells TEX to break the page.
If you wish to force TEX to break the page inside a paragraph,
without terminating the paragraph, you have to type
vadjust
break