Fixed-width font

• @code{…}, @samp{…}

  Use the @code{…} command when referring to individual, language-specific tokens (keywords, commands, engravers, Scheme symbols, etc.) in the text. Ideally, a single @code{…} block should fit within one line in the PDF output.

  Use the @samp{…} command when you have a short example of user input (for example, one or two letters), unless it constitutes an entire @item by itself, in which case @code{…} is preferable. Otherwise, both should only be used when part of a larger sentence within a paragraph or @item. Do not use @code{…} or @samp{…} inside an @example block, and do not use either as a free-standing paragraph; use @example instead.

  A single, unindented line in the PDF has space for about 79 fixed-width characters (76 if indented). Within an @item there is space for about 75 fixed-width characters. Each additional level of @itemize or @enumerate shortens the line by about 4 columns.

  However, even short blocks of @code{…} and @samp{…} can run into the margin if the Texinfo line-breaking algorithm gets confused. Additionally, blocks that are longer than this may in fact print nicely; it all depends where the line breaks end up. If you compile the documentation by yourself, check the PDF output to make sure the line breaks are satisfactory.

  The Texinfo setting @allowcodebreaks is set to false in the manuals, so lines within @code{…} or @samp{…} blocks will only break at spaces, not at hyphens or underscores. If the block contains significant spaces, use @w{@code{…}} or @w{@samp{…}} to prevent unexpected line breaks.

  The Texinfo settings txicodequoteundirected and txicodequotebacktick are both set in the manuals, so backticks (`) and apostrophes (') placed within blocks of @code, @example, or @verbatim are not converted to left- and right-angled quotes (‘ ’) as they normally are within the text, so the apostrophes in ‘@w{@code{\relative c''}}’ will display correctly. However, these settings do not affect the PDF output for anything within a @samp block (even if it includes a nested @code block), so entering ‘@w{@samp{\relative c''}}’ wrongly produces ‘\relative c’’’ in PDF. Consequently, if you want to use a @samp{…} block which contains backticks or apostrophes, you should instead use ‘@q{@code{…}}’ (or ‘@q{@w{@code{…}}}’ if the block also contains significant spaces).

• @command{…} – Use when referring to command-line commands within the text (e.g., ‘@command{convert-ly}’). Do not use inside an @example block.
• @example – Use for examples of program code. Do not add extraneous indentation (i.e., don’t start every line with whitespace). Use the following layout (notice the use of blank lines). Omit the @noindent if the text following the example starts a new paragraph:

  …text leading into the example…
  
  @example
  …
  @end example
  
  @noindent
  continuation of the text…
  

  Individual lines within an @example block should not exceed 74 characters; otherwise they will run into the margin in the PDF output, and may get clipped. If an @example block is part of an @item, individual lines in the @example block should not exceed 70 columns. Each additional level of @itemize or @enumerate shortens the line by about 4 columns.

  For long command-line examples, if possible, use a trailing backslash to break up a single line, indenting the next line with 2 spaces. If this isn’t feasible, use ‘@smallexample … @end smallexample’ instead, which uses a smaller font size. Use @example whenever possible, but if needed, @smallexample can fit up to 90 characters per line before running into the PDF margin. Each additional level of @itemize or @enumerate shortens a @smallexample line by about 5 columns.

• @file{…} – Use when referring to file names, file name extensions, and directories in the text. Do not use inside an @example block.
• @option{…} – Use when referring to command-line options in the text (e.g., ‘@option{--format}’). Do not use inside an @example block.
• @verbatim – Print the block exactly as it appears in the source file (including whitespace, etc.), without handling any Texinfo commands. The characters ‘@’, ‘{’, and ‘}’ don’t need to be quoted with a leading ‘@’ character. For program code examples, use @example instead. @verbatim uses the same format as @example.

  Individual lines within an @verbatim block should not exceed 74 characters; otherwise they will run into the margin in the PDF output, and may get clipped. If an @verbatim block is part of an @item, individual lines in the @verbatim block should not exceed 70 columns. Each additional level of @itemize or @enumerate shortens the line by about 4 columns.