.;	RUNOFF Chapter 5
.;
.;	H.R. Tumblin 7-Jan-78
.;
.CH;Source File Format
.in RNOCHAINI
.ix Source File Format
.pp
The source file contains the textual material which will appear on the
final copy, plus information to specify formatting. Most importantly,
upper and lower case information also may be supplied so that material
can be prepared on the terminal or other such device which can
normally input only upper case letters. All command information
consists of regular <ascii printing characters so that a listing of
the source file may be examined if the final copy is not exactly as
desired.
.pp
All material in the source file is taken to be source text except
those lines beginning with a period(.). A line beginning with a period
is assumed to be a command, and must match one of those listed. The
commands provide the formatting information, and control various
optional modes of operation.
.pp
Usually the text is filled
.ix Filling of text
and justified
.ix Justification of text
as it is processed. That is, the program <fills a line by adding
successive words from the source text until one more word would cause
the right margin to be exceeded. The line is then <justified by making
the word spacings larger until the last word in the line exactly meets
the right margin.
.PP
Formatting of a line with characters from a following line can be
prevented by creating what is called a "break". A "break" is caused
explicitly by the use of the break command, or it can be caused
implicitly by any of the commands that cause normal line spacing
to be interrupted. Breaking capabilities of each command can be found
in its complete description in the remainder of this manual.
.index Breaking Capabilities of Commands
.p
The user may occasionally wish to reproduce the source text
.ix Literals
exactly, which is done by disabling filling and justification or by
use of the <literal command. The program may be set to fill but not
justify, in which case the output will be normal except that lines
will not be justified to the right margin. The program may also be set
to justify but not fill, although this would probably produce peculiar
results and is not recommended.
.pp
When the fill mode is on, spaces, tabs,
.ix Space
.IX Word spacing
and carriage returns occurring in the source text are treated only as
word separators. Multiple separators are ignored.
.tp 10.s
The program will advance to new pages as necessary, placing
.ix Page Numbering
.ix Title
the title (if given) and the page number at the top of each page,
unless page numbering at the bottom of the page has been enabled. The
user may call explicitly for a page advance where desired, and may
inhibit the occurrence of a page advance within specified material.
.hl 1 Case Information
.ix Case Information
.PP
Specification of case(1) for files prepared on the terminal is done
with two characters, circumflex (%^, 136 octal), and back-slash (%\,
134 octal). The appearance of a circumflex causes the letter
immediately following to be transmitted in upper case. The appearance
of a back-slash causes the letter immediately following to be
converted to lower case. Any letter not preceded by one of these
characters is transmitted in the current mode. The mode is initially
upper case, and is changed by the occurrence of two successive case
control characters. Two circumflexes (%^%^) cause the mode to be set
to upper case, and two back-slashes (%\%\) cause the mode to be set to
lower case.
.S
.FN 10
.lm 8;.rm 80
.c;-------------------------
.br
.;
.i -4;-1- 
Case conversion takes place only on <ascii
codes 101 to 132 octal, that is, the upper case letters.  Any
actual lower case letters (codes 141 to 172 octal) appearing
in the source will be transmitted unchanged.
If the source is prepared by a terminal that has lowercase support,
then the mode should be set to uppercase at the beginning of
the file and left unchanged for the remainder.
!
The use of the above corresponds to the use of the shift and
shift-lock keys on a typewriter.  Usually, typing appears
in lower case. To type one letter in upper case, the shift
key is used.  The shift-lock is set to type a series of
upper case letters, after which it is released.
.tp 16.S
The following shows the uses of the case control characters:
.S
%^HERE IS A %^SAMPLE %^SENTENCE IN %^%^UPPER CASE%\%\ AND LOWER CASE.
.S
becomes:
.S
Here is a Sample Sentence in <upper <case and lower case.
.S
.;
.pg
.pp
An additional character, less-than (%<, 074 octal), capitalizes
the entire word it precedes. It then returns the file to the
current case.  This character is not engaged unless preceded by
the <flags <capitalize command.
.ix %< 
Similarly, the <flags <hyphenate command engages the special
.ix Hyphenation
character equals (%=, 075 octal), which causes hyphenation to be suspended
for the word it precedes.
.ix %=
.hl 1 Special Characters
.ix Special Characters
.;
.hl 2 Underscoring
%&######Ampersand#####Underscoring
.pp
The character ampersand (%&, 046 octal) is used to specify
underscoring.
.ix Underscoring
.IX %&
The ampersand will cause the character following it to be
underscored (e.g. %&f%&o%&o becomes ^&foo\&).
.pp
Underlining of a string of characters can also be specified,
similar to the use of the shift lock operations described above.
An appearance of ampersand preceded by circumflex (%^%&) will
cause underlining of all following characters except space. An
appearance of ampersand preceded by backslash (%\%&) will
disable this mode.
.;
.hl 2 Quoted Space
%######Number sign####Explicit or Quoted Space
.ix Quoted Space
.ix Explicit Space
.IX %#
.pp
It is occasionally necessary to include spaces in the text which
should not be treated as word separators. For this purpose, <runoff
treats the number-sign character (%#, 043 octal) as a quoted space;
i.e. it will print as exactly one space in the output, and will never
be expanded nor changed to a carriage return.
.;
.hl 2 Quote next character.
>##[_]##Greater than##Quote next character
.PP
To allow the appearance of the special characters (ampersand(%&),
number sign(%#), circumflex(%^), backslash(%\), greater than(%>), less
than(%<), exclamation point(%!), (%{) or equals sign(%=)) in the
output, the greater than character(>) is used as the quote character.
That is, the character immediately following an underscore will be
transmitted to the output file with no formatting effect. Thus the
following nine cases occur:
.ls
.la;>%&
.la;>%#
.la;>%^
.la;>%\
.la;>>###[>_]
.la;>%<
.la;>%=
.la;>%@###[>%{]
.la;>%~###[>%}]
.la;>%{
.la;>%!
.els
.ix Quote Next Character
.;
.hl 2 Upper case shift or mode lock.
%^####Circumflex####Upper case shift or mode lock.
.pp
As described in section 5.1, the circumflex character(%^) is
used to convert the letter following to upper case. It is
also used to lock the case mode in upper case, and in the
underlining mode to "underline all text".
.ix Upper Case Shift
.ix Mode Lock
.;
.tp 6
.hl 2 Lower case shift or mode unlock.
%\####Backslash####Lower case shift or mode unlock
.pp
As described in section 5.1, the backslash character(%\) is used to
output the letter following in lower case. It is also used to
lock the case mode in lower case, and to disable underlining.
.ix Lower Case Shift
.ix Mode Unlock
.;
.hl 2 Flags Capitalize.
%<####Less than character####Underline entire word.
.pp
If the command "FLAGS-CAPITALIZE" has been engaged, then all
words preceded with a less than character(%<) will be capitalized.
If it is to be used in printed text, then it also must be
preceded by the quote character.
.ix Flags Capitalize
.;
.hl 2 Flags Hyphenate.
%=####Equals sign####Hyphenation disable.
.pp
If the command "FLAGS-HYPHENATE" has been engaged, the equals
character(=) is used to disable hyphenation for the word
it precedes. If it is to appear in the printed text, then it
must be preceded by the quote character.
.ix Flags Hyphenate.
.;
.hl 2 Superscripting
%@#[%{]#at sign########Superscripting character
.pp
The at sign causes the next character to be placed a half a line above the
line being typed for a superscript.  This character works only if the DI or
ES switch is enabled.  Otherwise, the character is ignored.
.ix Superscript.
.;
.hl 2 Subscripting
%~#[%}]###Tilda##########Subscripting character
.pp
The %~ character causes the next character to be placed a half a line below
the line being typed for a subscript.  This character works only if the DI or
ES switch is enabled.  Otherwise, the character is ignored.
.ix Subscript
.;
.hl 2 Overstriking
%{######################Overstriking character
.pp
The %{ character causes the next printing character to overstrike the
preceding character.  To cause the next printing character to
overprint the preceding character, insert an "%{" between them.  The
slashed-zero appears in the input text as a 0%{/ or /%{0.  Note that
the backspace character (octal 10) CANNOT be used in the input file;
RNO will convert any backspace character in the input file into a "?"
in the output file.  Note this character only works for the Diablo,
if the /DI switch is not specified the two characters follow each
other, for example, a 0%{/ becomes a 0/.  
.ix Overstriking
.hl 2 In line comments
%!######################In line comment character
.pp
It is sometimes desireable to put comments in the text that do not
appear in the output documents.  Any text enclosed within exclamation
points (%!) will be treated as a comment and not printed in the
output.  Such a comment may appear in the middle of a line.
.ix In line comments
.;
.; End of chapter 5