Quick Guide to Understanding the Documentation
For the GPO
Photocomposition Coding Scheme
Of the U.S.
Code
The
GPO photocomposition code scheme was originally (in the mid-1970s) designed to
work on a GOP-modified version of the ATEX text editing system from Digital
Equipment Corp. The software to handle typesetting was the MTP
(�Multi-Typography Program�) developed in-house by GPO.� In 1996, the ATEX system in the Office of
the Law Revision Counsel was replaced with XYWrite (a PC-based clone of
ATEX).� At roughly the same time, the
MTP software was replaced by MicroComp (also developed in-house by GPO).
Photocomposition coded U.S. Code data consists of a stream of data with typesetting instructions contained in character strings that follow one of several special characters.� The most widely used command character is the bell (HEX 07).
Bell codes
A bell (HEX 07)
signals that a command is to be given.�
The character that immediately follows a bell indicates the type of
command.� Some of these commands have
arguments � these arguments come immediately after the character following the
bell.� For instance,
������ Bell-I80
is a bell-I with an argument of 80.� Note that the bell commands are case sensitive.
A brief description of each type of bell-code is contained
on the attached copy of page 4 of GPO Coding for Selected
Publications:� Standardized locator
lists and marked up samples showing how to key selected publications, U.S. Government Printing
Office, February 1988:
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Formats and
Locators (Bell-F, Bell-S, and Bell-I)
Formats are designated by a four- or five-digit number that follows a bell-F or bell-S.� Each format is associated with a set of definitions for 99 bell-I codes (bell-I01 to bell-I99).� The bell-I codes (often referred to as �locator codes�) retain their definitions as long as the format number does not change.� When the format number changes, the definitions for each of the locators codes change (e.g., the meaning of a locator-10 that occurs while the format is 5800 has a different meaning from a locator-10 that occurs while the format is 5804).
The following tables define the 99 locator codes associated with each U.S. Code format.� The headings of the table have the following meanings:
LOC��������������������������� locator code
PTSZ�������������������������� point
size
LDG��������������������������� leading (points from the baseline of one character to the baseline of the character above it)
LGH��������������������������� line length in points
INDENT PRI�������������� primary indent (the indent (in points) of the first line of a paragraph)
INDENT SEC������������ secondary indent (the indent (in
points) of all lines in a paragraph after the first line)
GRID�������������������������� grid call � see �Grids and Typefaces,�
below
TF������������������������������� typeface call � see �Grids and
Typefaces,� below
LNTP������������������������� line type (C = center, J = justify, L =
flush left, and R = flush right)
FOTP������������������������� format type (used to format rudimentary
tabular data, e.g., tables of contents) � if the previous locator code had a
numeric FOTP value and the current locator code has a numeric FOTP value that
is greater than the FOTP value of the previous locator code, then do not start
a new line.
RULE������������������������� if the RULE value is �R�, then generate a
horizontal rule.
(Additional definitions may be found in Publishing From a Full Text Data Base,�� Government Printing Office, Graphic Systems
Development Division, GPO Publication 200.4 (2nd edition), February
1983).
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There are no separate tables for formats 5801, 5802, and 5803, because the locator code definitions within those three formats are the same as the definitions for format 5800.[1]� For the most part, formats 5801 to 5803 are only used in U.S. Code appendices (e.g., the appendix to title 5).
Additional documentation is available for format 5800
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and
for format 5804
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With the format 5800 documentation, you should add
the following:
�
Locator-86
includes Presidential Proclamations, but does not include Reorganization Plans
�
Locator-87
includes Definition notes
Grids and Typefaces � bell-G, bell-g, bell-K, and bell-T
The typeface and type style (bold, italic, etc.) are specified by a combination of a grid call and a typeface call.� Each locator code contains a default grid and typeface value.� These values can be overridden however.� Bell-T followed by a one-digit argument will change the typeface call to the value of the argument.� Bell-G followed by a one-digit argument (or bell-g followed by a three digit argument) will change the grid call to the value of the argument.� A bell-K will change the typeface and grid calls back to the defaults specified by the last locator code.
When
the current grid is the result of a bell-g with a three-digit argument, then
the typeface and type style of the text are as set out in pages i to xvii of MicroComp Grid List, U.S. Government Printing Office, May 1996
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Of
the grids listed in MicroComp Grid List,
the U.S. Code currently uses grids 007, 025, 077,� 401, 710, 741, 742, and 940.
When
the value of the grid call is 1 to 4 and the current grid is the result of
either a bell-G or the default value from a locator code, then use the table in
the middle of page 4 of the format 5800 documentation, above.
When
the value of the current grid call is 5 to 8, use the following VideoComp table
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Titles, Chapters, Parts, etc. (bell-R)
A bell-R followed by two digits, indicates the start of a new grouping above the section level.� The two-digit argument indicates where the grouping sits within the hierarchy.� The lower the bell-R argument, the higher in the hierarchy the grouping is.� For example, a bell-R01 indicates the start of a new title � the highest hierarchical level within the U.S. Code.� By convention, bell-R05 is always used to indicate the start of a title appendix.
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Tables (�subformat generation�) � bell-c
Complex
tables start with a bell-c.� The end of
such a table is marked with a bell-e.�
In between a bell-c and a bell-e most of the rules for how to process
photocomposition codes are replaced with the special rules set out in Subformat Generation:� MicroComp, U.S. Government Printing
Office, February 1, 1997:
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An
addition to the 1997 documentation should be made on pages 2 and 5.� A bell-I97 has been added.� The bell-I97 does the same function as the
bell-I96, except that on a table that is continued on the next page (or column
of a page), a bell-I96 headnote will have ��continued� automatically appended
to the text of the headnote, whereas a bell-I97 headnote will not have
��continued� automatically appended.
Other Special Characters
In addition to the bell character, the following special characters are valid in Office of the Law Revision Counsel publications:
|
Name |
Hex Value |
Notes |
|
EOF |
00 |
End
of file |
|
Sectwst |
06 |
� |
|
Crlf |
0A |
Carriage
return � line feed |
|
Cents |
0B |
� |
|
Pgmark |
0C |
� |
|
Noprnst |
0E |
No
print � start |
|
Noprnend |
0F |
No
print � end |
|
Prime |
10 |
' |
|
Bldlbrak |
13 |
Bold
left bracket |
|
Bldrbrak |
14 |
Bold
right bracket |
|
Emspace |
18 |
M-space |
|
Enspace |
19 |
N-space |
|
Plusminus |
1B |
� |
|
Dscrhyph |
1C |
Discretionary
hyphen |
|
Dagger |
1E |
� |
|
Xquotes
(open) |
27 |
� |
|
Less
than |
3C |
< |
|
Greater
than |
3E |
> |
|
Footnote |
5C |
Convert
numbers between footnote characters (backslashes) into superscripts |
|
minus |
5E |
- |
|
Emdash |
5F |
� |
|
Xquotes
(close) |
60 |
� |
|
Degreemk |
AB |
� |
|
Dbldagger |
BD |
� |
|
Muchless |
BE |
n |
|
Balbox |
BF |
□ |
An
escape character (Hex FF) followed by the following two (or three) characters
represents the following characters
|
Name |
ESC sequence |
Notes |
|
Thin
space |
ESC
1A |
Thin
space |
|
N-dash |
ESC
09 |
N-dash |
|
Multiplication |
ESC
0A |
H |
|
All
Mark |
ESC
08 |
O |
|
Copyright |
ESC
AF |
� |
|
AC_BREVE |
ESC
AE0 |
˘ |
|
AC_ACUTE |
ESC
AE1 |
΄ |
|
AC_GRAVE |
ESC
AE2 |
` |
|
AC_CIRCUMFLEX |
ESC
AE3 |
^ |
|
AC_DIERESIS |
ESC
AE4 |
� |
|
AC-CARON |
ESC
AE5 |
ˇ |
|
AC_TILDE |
ESC
AE6 |
~ |
|
AC_ANGSTROM |
ESC
AE7 |
˚ |
|
AC_MACRON |
ESC
AE8 |
ˉ |
|
AC_CEDILLA |
ESC
AE9 |
� |
XHTML Conversion
All of the above documentation provides explanations for each of the
photocomposition codes used in the U.S. Code.�
Below is a proposed specification for converting U.S. Code
photocomposition codes into XHTML
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