###### 3.1.1.2.15 fn

Use footnote (<fn>) to annotate text with notes that are inappropriate for inline inclusion or to indicate the source for facts or other material used in the text.

Footnote content is skipped at the place where it was entered and rendered elsewhere, according to these rules:

- A footnote with no given id attribute is a single-use footnote. Upon output, it generates a number as a superscript “callout” that is linked to the placement of the footnote, such as at the bottom of the immediate printed page or at the end of an online article. If a character is specified in the callout attribute for the footnote, that character should be used as the superscript “callout” that is linked to the placement of the footnote.
- A footnote entered with an id attribute is a use-by-reference footnote. Upon output, it does not appear anywhere unless it has been referenced using an <xref> with the type attribute set to “fn”.
- Ordinarily, a footnote in one topic can't be referenced in another topic. The previous behaviors are local to each topic. But by using the conref mechanism, you can create a new copy of another topic's footnote within the local topic where it will then follow these behaviors:
  - If you use <fn conref="file.dita#topic/thatid"></fn> all by itself, the result will be the same as the single-use footnote entered literally in the same location. That is, it creates a local copy of the footnote with no local id attribute, so it uses the behavior from the first bullet above.
  - If you use <fn conref="file.dita#topic/thatid" id="thisid"></fn>, followed by <xref href="#thistopic/thisid" type="fn"/>, the result will be the same as the use-by-reference model described in the second bullet. That is, the <fn> element creates a local copy of the footnote with an id of "thisid"; that local copy is then referenced by the <xref> element.

The details of footnote processing and styling are implementation and/or stylesheet dependent. For example, a tool that renders DITA as PDF may lack support for the callout attribute, or footnotes may be collected as endnotes for certain types of publications.

###### Contains

Doctype | Content model
topic (base), map (base), classifyMap, subjectScheme, learningBookmap, learningMap | ( text data or dl or fig or imagemap or image or lines or lq or note or hazardstatement or object or ol or p or pre or sl or ul or boolean or cite or keyword or ph or b or i or sup or sub or tt or u or q or term or tm or xref or state or data or data-about or foreign or unknown) (any number)
topic (technical content), map (technical content), concept, ditabase, glossary, glossentry, glossgroup, reference, task, bookmap | ( text data or dl or parml or fig or syntaxdiagram or imagemap or image or lines or lq or note or hazardstatement or object or ol or p or pre or codeblock or msgblock or screen or sl or ul or boolean or cite or keyword or apiname or option or parmname or cmdname or msgnum or varname or wintitle or ph or b or i or sup or sub or tt or u or codeph or synph or filepath or msgph or systemoutput or userinput or menucascade or uicontrol or q or term or abbreviated-form or tm or xref or state or data or data-about or foreign or unknown) (any number)
machineryTask | ( text data or dl or fig or imagemap or image or lines or lq or note or hazardstatement or object or ol or p or pre or screen or sl or ul or boolean or cite or keyword or wintitle or ph or b or i or sup or sub or tt or u or menucascade or uicontrol or q or term or tm or xref or state or data or data-about or foreign or unknown) (any number)
learningAssessment, learningContent, learningOverview, learningPlan, learningSummary | ( text data or dl or fig or imagemap or lcInteractionBase or lcTrueFalse or lcSingleSelect or lcMultipleSelect or lcSequencing or lcMatching or lcHotspot or lcOpenQuestion or image or lines or lq or note or lcInstructornote or object or ol or p or pre or sl or ul or boolean or cite or keyword or ph or b or i or sup or sub or tt or u or q or term or tm or xref or state or data or data-about or foreign or unknown) (any number)

###### Contained by

Doctype | Content model
topic (base) | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example
map (base), classifyMap, subjectScheme, learningMap | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry
topic (technical content), concept | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, screen, codeblock, pd
map (technical content) | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, screen, codeblock, pd
ditabase | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, prereq, context, steps-informal, stepsection, cmd, info, tutorialinfo, stepxmp, choice, choptionhd, chdeschd, choption, chdesc, stepresult, result, postreq, refsyn, proptypehd, propvaluehd, propdeschd, proptype, propvalue, glossdef, glossUsage, glossScopeNote, screen, codeblock, pd
glossary, glossentry, glossgroup | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, glossdef, glossUsage, glossScopeNote, screen, codeblock, pd
reference | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, refsyn, proptypehd, propvaluehd, propdeschd, proptype, propvalue, screen, codeblock, pd
task (strict), task (general) | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, prereq, context, steps-informal, stepsection, cmd, info, tutorialinfo, stepxmp, choice, choptionhd, chdeschd, choption, chdesc, stepresult, result, postreq, screen, codeblock, pd
bookmap | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, organizationname, screen, codeblock, pd
machineryTask | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, prereq, context, steps-informal, stepsection, cmd, info, tutorialinfo, stepxmp, choice, choptionhd, chdeschd, choption, chdesc, stepresult, result, postreq, reqcond, reqcontp, personnel, perscat, perskill, esttime, supequi, supply, spare, safecond, screen
learningAssessment, learningOverview, learningSummary | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, lcIntro, lcObjectivesStem, lcObjective, lcAudience, lcTime, lcPrereqs, lcSummary, lcNextSteps, lcReview, lcResources, lcChallenge, lcInstruction, lcInteractionBase, lcQuestionBase, lcInstructornote, lcQuestion, lcOpenAnswer, lcFeedback, lcFeedbackCorrect, lcFeedbackIncorrect, lcAnswerContent, lcItem, lcMatchingItem
learningBookmap | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, organizationname
learningContent | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, lcIntro, lcObjectivesStem, lcObjective, lcAudience, lcTime, lcPrereqs, lcSummary, lcNextSteps, lcReview, lcResources, lcChallenge, lcInstruction, prereq, context, steps-informal, stepsection, cmd, info, tutorialinfo, stepxmp, choice, choptionhd, chdeschd, choption, chdesc, stepresult, result, postreq, refsyn, proptypehd, propvaluehd, propdeschd, proptype, propvalue, lcInteractionBase, lcQuestionBase, lcInstructornote, lcQuestion, lcOpenAnswer, lcFeedback, lcFeedbackCorrect, lcFeedbackIncorrect, lcAnswerContent, lcItem, lcMatchingItem
learningPlan | p, note, lq, sli, li, itemgroup, dd, fig, figgroup, pre, lines, ph, stentry, entry, abstract, bodydiv, section, sectiondiv, example, lcIntro, lcObjectivesStem, lcObjective, lcAudience, lcTime, lcPrereqs, lcSummary, lcNextSteps, lcReview, lcResources, lcChallenge, lcInstruction, lcClient, lcPlanTitle, lcCIN, lcModDate, lcDelivDate, lcPlanSubject, lcPlanDescrip, lcPlanPrereqs, lcGeneralDescription, lcGoals, lcNeeds, lcValues, lcOrgConstraints, lcEdLevel, lcAge, lcBackground, lcSkills, lcKnowledge, lcMotivation, lcSpecChars, lcWorkEnvDescription, lcPlanResources, lcProcesses, lcTaskItem, lcAttitude, lcPlanObjective, lcJtaItem, lcGapItemDelta, lcLearnStrat, lcAssessment, lcDelivery, lcLMS, lcNoLMS, lcHandouts, lcClassroom, lcOJT, lcConstraints, lcW3C, lcPlayers, lcGraphics, lcViewers, lcResolution, lcFileSizeLimitations, lcDownloadTime, lcSecurity, lcInteractionBase, lcQuestionBase, lcInstructornote, lcQuestion, lcOpenAnswer, lcFeedback, lcFeedbackCorrect, lcFeedbackIncorrect, lcAnswerContent, lcItem, lcMatchingItem

###### Inheritance

- topic/fn

###### Example

The first example is of a single-use footnote. It uses a simple fn element, with no ID and no callout attribute. In that case, markup such as the following:

    The memory storage capacity of the computer is
    2 GB<fn>A GB (gigabyte) is equal to
    1000 million bytes</fn> with error correcting support.may produce output similar to the following:

The memory storage capacity of the computer is 2 GB 1 with error correcting support.

......

1 A GB (gigabyte) is equal to 1000 million bytes

----- [bottom of page] -----------------------------------------------------------------

The second example is a single-use footnote that uses a callout attribute. It is marked up as follows:

    The memory storage capacity of the computer is
    2 GB<fn callout="#">A GB (gigabyte) is equal to
    1000 million bytes</fn> with error correcting support.That DITA markup may produce output similar to the following:

The memory storage capacity of the computer is 2 GB# with error correcting support.

......

# A GB (gigabyte) is equal to 1000 million bytes

----- [bottom of page] -----------------------------------------------------------------

The third example is a use-by-reference footnote. It uses an ID on a footnote, and then references that ID multiple times. The DITA markup looks like this:

    I like pets. <fn id="reuse-fn">This is the name of an animal.</fn>
    At my house, I have a dog<xref href="#topic/reuse-fn" type="fn"/>, a
    cat<xref href="#topic/reuse-fn" type="fn"/>, and a
    llama<xref href="#topic/reuse-fn" type="fn"/>.and may produce output similar to the following:

I like pets. At my house, I have a dog 1, a cat 1, and a llama 1.

......

1This is the name of an animal.

----- [bottom of page] -----------------------------------------------------------------

###### Attributes

Name | Description | Data Type | Default Value | Required?
callout | Specifies what character is used for the footnote link, for example a number or an alpha character. The attribute may also specify a short string of characters. When no callout value is specified, footnotes are numbered. | CDATA | #IMPLIED | No
univ-atts attribute group (includes select-atts, id-atts, and localization-atts groups) | A set of related attributes, described in 3.4.1.3 univ-atts attribute group |  |  |
global-atts attribute group (xtrf, xtrc) | A set of related attributes, described in 3.4.1.2 global-atts attribute group |  |  |
class, outputclass | Common attributes described in 3.4.1.9 Other common DITA attributes |  |  |

Previous Topic: 3.1.1.2.14 figgroup

Next Topic: 3.1.1.2.16 image

Parent Topic: 3.1.1.2 Body elements

Sibling Topics:

3.1.1.2.1 alt

3.1.1.2.2 cite

3.1.1.2.3 dd

3.1.1.2.4 desc

3.1.1.2.5 ddhd

3.1.1.2.6 dl

3.1.1.2.7 dlentry

3.1.1.2.8 dlhead

3.1.1.2.9 dt

3.1.1.2.10 draft-comment

3.1.1.2.11 dthd

3.1.1.2.12 example

3.1.1.2.13 fig

3.1.1.2.14 figgroup

3.1.1.2.16 image

3.1.1.2.17 keyword

3.1.1.2.18 li

3.1.1.2.19 lines

3.1.1.2.20 longdescref

3.1.1.2.21 longquoteref

3.1.1.2.22 lq

3.1.1.2.23 object

3.1.1.2.24 note

3.1.1.2.25 ol

3.1.1.2.26 p

3.1.1.2.27 param

3.1.1.2.28 ph

3.1.1.2.29 pre

3.1.1.2.30 q

3.1.1.2.31 section

3.1.1.2.32 sectiondiv

3.1.1.2.33 sl

3.1.1.2.34 sli

3.1.1.2.35 term

3.1.1.2.36 text

3.1.1.2.37 tm

3.1.1.2.38 ul

3.1.1.2.39 xref