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. 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 ? AC_TILDE ESC AE6 ~ AC_ANGSTROM ESC AE7 ° AC_MACRON ESC AE8 ¯ 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