This element allows the full capabilities of the HTML style attribute to be applied to the title of a questionnaire, or to the label or text of a questionnaire item or to the label of an option. This might mean changing the font or color, changing font style such as bold, italics, small caps, etc. Conformant systems are allowed to ignore this extension unless the rendering-styleSensitive flag is set to true.

This element provides an alternate representation of the string value of the extended element that makes use of a subset XHTML. (Specifically, the XHTML subset allowed by the core specification.) This extension allows applying different styles to different portions of the text (via <span/>, <b/> and similar elements). It also allows embedding structure elements such as bullets or even tables in item.text elements. XHTML must be base64-encoded due to constraints on the values of extensions. For title and label, the XHTML should be an inline element, while text can also include block-level elements (paragraph, ul/ol, etc.). Conformant systems are allowed to ignore this extension unless the rendering-styleSensitive flag is set to true.

For items with a type of 'display', this indicates what kind of display item it is so that systems can apply differential formatting based on the purpose of the display element. In the absence of a declared itemControl this could influence the mechanism used to render the display text (e.g. help-button or separate page for help text). Regardless of the presence of itemControl, it can also influence the formatting of the text. For example, instructions might appear in a different font than security rules or with a different background or different surrounding box. The specific means of display are left open to the form filler, however systems that support this extension SHALL visually distinguish display items with different categories.

For items with a type of 'open-choice', this extension provides a label text to display beside the free-text and/or unrestricted type values. E.g. 'Other, please specify', or 'Additional condition', or 'More reason(s)', etc.

This allows flagging items that should not be displayed at all. In theory, it can be used for any item, but in general, it only makes sense for questions and groups. It allows for answers to be captured behind the scenes using the behavior and/or population mechanisms. For example, hidden scores, hidden source data, hidden data needed for extraction. If an item is hidden, then all items below it will be hidden as well. Hidden items are automatically treated as readOnly - users cannot edit what they cannot see or navigate to.

NOTE: Hiding data from the enterer is not a solution to data privacy/security concerns as any questionnaire answer must be presumed to be potentially available to any consumer of the questionnaire in some manner.

Media to render/make available accompanying the question being asked or group or display item being rendered.

Media to render/make available as an accompaniment to a specific answer option.

This allows the selection of a specific control type for the answer for a group, question or display item. The set of available codes has specific sub-sets for group, display and question items. Those for group provide control over how the child items within the group are organized or where the group appears within the overall questionnaire (e.g. as a header or footer). The 'text' items provide guidance about how the display item should be rendered, including relative position with respect to the question and answer and by what mechanism the display text should be rendered (fly-over, help-button, overlay on control or simple in-line text). Finally, the 'question' items allow the choice of control for selecting an answer. For choice, open-choice, and Reference items, it allows autocomplete, drop-down, check-box, radio-button and lookup controls. For numerics, dates and times, slider and spinner controls are also options, as well as the more traditional text-box.

When groups are rendered as tables, the width and choiceColumn extensions can help control the formatting of the table.

Normally, it's up to the render to determine whether to display choices horizontally or vertically or to define multiple columns of choice options. This extension allows forcing the choices to be rendered horizontally or vertically. Also see the columnCount entry.

For questions with a type of 'integer' and a itemControl of 'slider', this allows indicating the increment with which the slider will move between the minValue and the maxValue. For example, incrementing by 2, by 5, by 10, etc. Only values at the specified interval increments can be selected as answers.

This is used for question items that are the child of a group item with an itemControl whose value is 'htable' or 'gtable' - i.e. where each question within the group occupies a column. This extension identifies what the permitted width is for the column that contains the question. It can either be specified as a percentage of the overall table width (quantity.code = '%' and system='http://unitsofmeasure.org') or pixels (quantity.code and system are omitted). See choiceColumn for guidance on setting column widths for choice-based columns.

This allows the child items of a group or question item to be displayed in a collapsible form (toggle between showing and hiding the child items). This is very useful for authors dealing with particularly long questionnaires. The author might choose to present certain sections collapsed which will provide the user brief overviews before digging into nested items.

This extension is used with checkboxes and radio buttons to indicate that the list of choices should be split into multiple columns. The list of options will be spread (as evenly as possible) across the number of columns indicated. This extension works with choiceOrientation, in that if the list is horizontally oriented, the options will first list across columns and then after hitting the indicated number of columns will start again at the next row in the first column. I.e. "list choices across first". On the other hand, if the list is vertically oriented, choices will be listed down the first column, then the next column, then the last column, aiming to balance the number of entries in the columns, with the last column possibly having fewer items.

This allows associating a link to a question, group or display item. When this extension is present, an icon indicating that a link is available should appear immediately following the text of the item. Clicking on the link will allow the user to navigate to additional descriptive detail, generally on a separate page/tab. This extension allows the use of links without injecting the need to support full HTML via the rendering-xhtml extension (which would also allow hyperlinks, though they could appear at any point within the text and would provide control over the text or image used to launch the link).

This extension is used when users are selecting from a list of possible choices and there's a desire to control what information is displayed in the list of possible candidates. It has two modes of operation:

With choice and open-choice, it allows selection of display names and/or code system properties that should appear. For example, if a 'Medication' code system includes properties for form, preferred route and strength, that information could be displayed alongside the 'display name' for the item. Alternatively, a questionnaire might present the display names for the concept in English, Spanish and French. The path is set to 'display' for the code's standard display name. It's set to the property.code for a property value. It's set to the language code for designations in a particular language (only works if there's only one designation for the language). It's set to the designation use code for a selected designation (only works if there's only one designation for that use).

With a Reference it allows selection of fields from the resource - for example the first name, last name and phone number of a provider. The path is the FHIRPath to navigate to the element from the resource root. For example name.first().given.first() for the first name of a Patient or Practitioner.

Regardless of the item.type, multiple repetitions of the extension can be specified to indicate multiple columns. The columns are displayed in the same order as the extensions appear on the Questionnaire.item. For each column, the extension indicates the label to be displayed at the top of the column and the width of the column (following the same guidelines as for width). It's also possible to indicate which column(s) should be used to construct the Coding.display or Reference.display value. For choice and open-choice which map to Coding, only one extension repetition can have 'forDisplay' set to 'true'. That column must either have a path of 'display' or must specify the language or use of a code designation (i.e. not a code property). For Reference items, if multiple columns are marked with 'forDisplay', the display value used will be a space-separated concatenation of all columns so-marked.

NOTE: If no 'forDisplay' columns are marked, or no columns are listed for a Reference questionnaire item, it's up to the form filler to decide what to display and what, if anything, to capture in the display element.

This allows declaring a prefix to be displayed in front of an option (e.g. "(a)", or "1."). It can be defined for options listed directly in the question, but also for entries in value sets referenced by a question. (Note that these prefixes can also be supplemented with the rendering-style and rendering-xhtml extensions.

This serves the same purpose as optionPrefix, but allows the definition of the prefix to occur in a valueset referenced by answerValueSet instead of listing the options directly using answerOption.

This provides a string that helps to guide entry of formatted text and often appears directly "behind" the control to be filled. For example, "nnn-nnn-nnnn" for a North American phone number, "YYYY-MM-DD" for a date, "nnnn nnnn nnnn nnnn" for certain types of credit card numbers, etc.

This provides a short text for an item. This is useful as an alternate display when rendering the questionnaire on smaller devices like a mobile phone.

Both groups and questions can be marked as 'required'. For groups, that at least one question within a given repetition of the group must have an answer. For questions, it means the question must have at least one answer. Typically, items that are 'required' will have a visual cue indicating this. It could be managed by changing the background of the answer control, bolding the question text, or some other mechanism.

Also see guidance for this element on the behavior page.

Both groups and questions can be marked as repeating. For groups, that means all content within the group can be repeated multiple times. The itemControl extension can give specific guidance about this, for example treating each repetition as a row in a table. Without guidance, it's up to the Form Filler to decide how to handle allowing the creation of additional repetitions (or their removal) and how to handle labeling the questions within - whether they should be repeated on each repetition or just listed once for the first occurrence.

For questions that are marked as repeating, the results will be captured as multiple answers for one question. In many cases, the question text will only need to appear once, and the user can fill in as many answers as they like. However, for question items that contain nested questions, it may be necessary to repeat the question text for each repetition to ensure that it still appears on the user's screen.

Also see guidance for this element on the behavior page.

If an element is read-only, it means the user cannot adjust the value which can mean a change to the control used to render the form. Technically there's no need to display a text box, drop-down or other controls if the value cannot be changed. However, it's generally still desirable to use the same controls so that it's clear that the question answer is still an "answer" and so that read-only information does not stand out significantly from other answers. However, there should still be a visual indicator that the element cannot be edited. This might include changing the background color, changing the font for the question text or some similar visual cue.

Also see guidance for this element on the behavior page.

If set to true, this indicates that the 'style' information conveyed by the rendering-style and/or rendering-xhtml are considered critical to the accurate rendering of the questionnaire (and appropriate capture of information using the questionnaire). For example, there are instructions or other text that refer to specific colors or styles and a user would not be able to fill out the questionnaire safely or appropriately if those colors or styles are not accurately rendered. As a result, only systems that can render all such extensions appropriately are considered 'safe' to render the Questionnaire. All other SDC systems SHALL raise an error.

This inter-version extension pre-adopts the FHIR R5 data element and allows control over the appearance of elements that are 'disabled' due to an enableWhen (or enableWhenExpression) that evaluates to false. It indicates whether disabled content should be hidden (not visible to the user) or should remain visible but simply be disabled, keeping the content from being edited but still allowing the user to see the questions that *could* have been asked.

The 'hidden' option makes for a visually simpler form and may also avoid tempting users to change their answers based on what options were disabled based on their previous selections. However, sometimes it is important that the user *does* have the ability to go back and change their answers if they realize that the disabled questions are relevant.