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:
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).
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
and
for format 5804
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
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
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.
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:
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 |
º |
|
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