May be formatted inline or as a displayed block, depending on context. It is not usually rendered where it occurs, rather it is used to annotate some other aspect of the presentation.

For example, in an HTML presentation, the alt for a media object would likely provide the text of the alt attribute for the HTML img element.

In the context of an acronym, the alt could provide the title attribute for the HTML abbr element allowing the expansion to be presented appropriately to the user (as a “tooltip”, for example, or read aloud).

Common attributes.

any attribute

Any attribute in any other explicit namespace

These elements contain alt: abbrev, accel, acronym, address, application, area (db.area), area (db.area.inareaset), arg, artpagenums, attribution, authorinitials, bibliocoverage, biblioid, bibliomisc, bibliomixed, bibliomset, bibliorelation, bibliosource, bridgehead, buildtarget, caption (db.html.caption), citation, citebiblioid, citetitle, city, classname, classsynopsisinfo, code, command, computeroutput, confdates, confnum, confsponsor, conftitle, constant, contractnum, contractsponsor, contrib, country, database, description, edition, email, emphasis (db._emphasis), emphasis (db.emphasis), entry, enumidentifier, enumitemdescription, enumname, enumvalue, envar, equation, errorcode, errorname, errortext, errortype, exceptionname, fax, filename, firstname, firstterm (db._firstterm), firstterm (db.firstterm), foreignphrase (db._foreignphrase), funcdef, funcparams, funcsynopsisinfo, function, givenname, glosssee, glossseealso, glossterm (db._glossterm), glossterm (db.glossterm), guibutton, guiicon, guilabel, guimenu, guimenuitem, guisubmenu, hardware, holder, honorific, informalequation, informaltable (db.cals.informaltable), initializer, inlineequation, inlinemediaobject, interfacename, issuenum, jobtitle, keycap, keycode, keysym, label, lineage, lineannotation, link, literal, literallayout, macroname, manvolnum, markup, mathphrase, mediaobject, member, meta (db.meta.content), methodname, modifier, mousebutton, msgaud, msglevel, msgorig, olink, option, optional, orgdiv, orgname, otheraddr, othername, package, pagenums, para, paramdef, parameter, personname, phone, phrase (db._phrase), phrase (db.phrase), pob, postcode, primary, primaryie, productname, productnumber, programlisting, prompt, property, publishername, quote (db._quote), quote (db.quote), refdescriptor, refentrytitle, refmiscinfo, refname, refpurpose, releaseinfo, remark, replaceable, returnvalue, revnumber, revremark, screen, secondary, secondaryie, see, seealso, seealsoie, seeie, seg, segtitle, seriesvolnums, shortaffil, simpara, specializedtemplate, state, street, subscript, subtitle, superscript, surname, symbol, synopsis, synopsisinfo, systemitem, table (db.cals.table), tag, td, template, templatename, term, termdef, tertiary, tertiaryie, th, title, titleabbrev, tocentry, token, trademark, type, typedefname, unionname, uri, userinput, varname, volumenum, wordasword, year.

The following elements occur in alt: text, inlinemediaobject.