Formatted as a displayed block. This element is displayed “verbatim”; whitespace and line breaks within this element are significant. The programlistings are usually displayed in a fixed-width font.

Other markup within a programlisting is recognized. Contrast this with systems like LaTeX, in which verbatim environments disable markup recognition. If you want to disable markup recognition, you must use a CDATA section:

1 |<programlisting><![CDATA[This is a programlisting so white       space and line
  |breaks are significant.  But it is also a CDATA
  |section so <emphasis>tags</emphasis> and &entities;
  |are not recognized.  The only markup that is recognized
5 |is the end-of-section marker, which is two
  |"]"'s in a row followed by a >.
  |]]></programlisting>

Two markup tags have special significance in programlistings: co and lineannotation. A co identifies the location of a callout. A lineannotation is a comment, added by the documentor—not the programmer.

Common attributes and common linking attributes.

any attribute

Any attribute in any other explicit namespace

continuation

Determines whether line numbering continues from the previous element or restarts

Enumerated values:
“continues”	Line numbering continues from the immediately preceding element with the same name.
“restarts”	Line numbering restarts (begins at 1, usually).

language

Identifies the language (i.e. programming language) of the verbatim content

linenumbering

Determines whether lines are numbered

Enumerated values:
“numbered”	Lines are numbered.
“unnumbered”	Lines are not numbered.

startinglinenumber

Specifies the initial line number

width

Specifies the width (in characters) of the element

xml:space

Can be used to indicate explicitly that whitespace in the verbatim environment is preserved. Whitespace must always be preserved in verbatim environments whether this attribute is specified or not

Enumerated values:
“preserve”	Whitespace must be preserved.

These elements contain programlisting: abstract, acknowledgements, annotation, answer, appendix, article, bibliodiv, bibliography, bibliolist, blockquote, callout, calloutlist, caption (db.caption), caution, chapter, colophon, constraintdef, cover, danger, dedication, entry, example, figure, footnote, glossary, glossdef, glossdiv, glosslist, important, index, indexdiv, informalexample, informalfigure, itemizedlist, legalnotice, listitem, meta (db.meta.content), msgexplan, msgtext, note, orderedlist, para, partintro, preface, procedure, programlistingco, qandadiv, qandaset, question, refsect1, refsect2, refsect3, refsection, refsynopsisdiv, result, revdescription, sect1, sect2, sect3, sect4, sect5, section, setindex, sidebar, simplesect, step, taskprerequisites, taskrelated, tasksummary, td, textobject, th, tip, toc, tocdiv, topic, variablelist, warning.

The following elements occur in programlisting: text, abbrev, accel, acronym, alt, anchor, annotation, application, author, biblioref, buildtarget, citation, citebiblioid, citerefentry, citetitle, classname, co, code, command, computeroutput, constant, coref, database, date, editor, email, emphasis (db._emphasis), emphasis (db.emphasis), enumidentifier, enumname, enumvalue, envar, errorcode, errorname, errortext, errortype, exceptionname, filename, firstterm (db._firstterm), firstterm (db.firstterm), footnote, footnoteref, foreignphrase (db._foreignphrase), foreignphrase (db.foreignphrase), function, glossterm (db._glossterm), glossterm (db.glossterm), guibutton, guiicon, guilabel, guimenu, guimenuitem, guisubmenu, hardware, indexterm (db.indexterm.endofrange), indexterm (db.indexterm.singular), indexterm (db.indexterm.startofrange), info (db.titleforbidden.info), initializer, inlineequation, inlinemediaobject, interfacename, jobtitle, keycap, keycode, keycombo, keysym, lineannotation, link, literal, macroname, markup, menuchoice, methodname, modifier, mousebutton, nonterminal, olink, ooclass, ooexception, oointerface, option, optional, org, orgname, package, parameter, person, personname, phrase (db._phrase), phrase (db.phrase), productname, productnumber, prompt, property, quote (db._quote), quote (db.quote), remark, replaceable, returnvalue, revnumber, shortcut, subscript, superscript, symbol, systemitem, tag, templatename, termdef, textobject, token, trademark, type, typedefname, unionname, uri, userinput, varname, wordasword, xref.