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Action Tags Overview

Action Tags — Overview

Article ID RC-AT-01 — Action Tags: Overview
Domain Action Tags
Applies To All REDCap project types; requires Project Design and Setup rights
Prerequisite RC-FD-02 — Online Designer; foundational Project Build & Management knowledge
Version 1.0
Last Updated 2026
Author See KB-SOURCE-ATTESTATION.md
Related Topics RC-AT-02 — @HIDDEN & @READONLY — Visibility Control through RC-AT-07 — Cosmetic Action Tags (category articles); RC-FD-02 — Online Designer; RC-FD-03 — Data Dictionary

1. Overview

This article introduces REDCap's action tags feature — what action tags are, why they exist, how to find the ones available in your project, and the three ways to add them to a field. It is the entry point for the Action Tags knowledge base series.

2. Key Concepts & Definitions

Action Tag

A short keyword starting with @ that is placed in the Action Tags / Field Annotation box of a REDCap field. Action tags modify the standard behavior of that field. For example, @HIDDEN hides the field from view; @WORDLIMIT=10 caps input at ten words.

Parameter

Some action tags require additional information to function. Parameters are placed immediately after the tag name, inside quotes or parentheses depending on the tag. For example, @HIDECHOICE='1' hides the option with raw value 1. Tags without parameters (e.g., @HIDDEN) are used on their own.

Raw Value

The internal code assigned to each option in a radio button, dropdown, or checkbox field. Raw values are set in the Online Designer and are distinct from the option labels that users see. Several action tags use raw values in their parameters.

Field Annotation

Free-form notes that can be placed in the same Action Tags / Field Annotation box alongside any action tag. Annotations are only visible in the Online Designer and the Data Dictionary — they are never shown to data entry users or survey participants, and they have no effect on field behavior. Use annotations for designer-facing notes: design rationale, outstanding questions, variable mapping notes, or reminders about protocol decisions.

Do not confuse with the Field Note. The Field Note (a separate field attribute) is visible to everyone completing the instrument. The Field Annotation is visible to designers only. If you need to communicate something to the person filling in the form — such as units of measure or format instructions — use the Field Note, not the Field Annotation. See RC-FD-06 — Online Designer – Instrument and Field Management Section 7.8–7.9 and the project STYLE-GUIDE.md for guidance on which to use when.

External Module Action Tags

Third-party External Modules can introduce additional action tags beyond REDCap's standard set. The Action Tags series covers only the action tags that ship with REDCap.

3. What Action Tags Do

Action tags were introduced to change the default behavior of individual REDCap fields without requiring additional buttons or settings in the interface. The system is intentionally lightweight and extensible: new action tags are added with REDCap upgrades, and as of version 15.x there are over fifty standard tags.

Every action tag shares three characteristics:

  • They change field behavior. Each tag modifies something specific — hiding a field, capping word count, pre-filling a value, and so on.
  • They are situational. Most tags only work for specific field types or in specific contexts (e.g., survey mode only). Adding a tag to an incompatible field type typically has no effect; no error is generated.
  • Their effects can be combined. Multiple action tags can be placed in the same annotation box, separated by spaces. Their effects stack.

4. Finding Available Action Tags

The action tags available to you depend on your REDCap version and any External Modules installed on your instance. The built-in reference is the most reliable way to see what is available.

Red @ Action Tags buttons appear in several places throughout REDCap:

  • The Project Setup page
  • The Online Designer (top-right corner of the instrument field list)
  • The Edit Field popup for any individual field

All of these buttons open the same popup, which lists every currently available action tag along with a description of its purpose and usage. When opened from the Edit Field popup, the list also shows an Add button that inserts the selected tag directly into the annotation box.

Pro tip: Select View text on separate page (top-right of the popup) to open the reference in a new browser tab so you can keep it open while configuring fields.

Pro tip: New action tags are added with each REDCap upgrade. Check this reference after every upgrade to see what is new.

5. How to Add an Action Tag

There are three ways to add action tags to a field.

5.1 Individually — Edit Field Dialog

Open the Edit Field popup in the Online Designer and type the action tag into the red Action Tags / Field Annotation box. Tags always start with @. Some need only their name (e.g., @HIDDEN); others require a parameter (e.g., @HIDECHOICE='1').

5.2 In Bulk — Quick-Modify Field(s)

Most fields in the Online Designer have a checkbox in their top-right corner. Selecting one or more of these checkboxes opens the Quick-Modify Field(s) popup. Click the @ button within that popup to open the Edit Action Tags? menu, which applies changes to all selected fields at once:

Option Effect
Clear Removes all action tags from the selected fields
Add Adds the entered action tags to all selected fields
Deactivate Temporarily disables action tags (useful during testing)
Reactivate Re-enables any deactivated action tags
Copy Copies the action tags from the last-checked field to all other selected fields
Edit Opens the standard edit dialog for the last-checked field only

Click Apply to confirm any changes.

5.3 Via the Data Dictionary

The Action Tags / Field Annotation column (column R in Excel) in the Data Dictionary accepts action tags exactly as the Online Designer does. However, most spreadsheet applications interpret the @ character as a formula prefix and may prevent editing. To work around this, format column R as Text before making edits.

6. Action Tag Quick Reference

Use this table to quickly find which article covers a specific action tag.

Action Tag Category Article Purpose
@HIDDEN Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Hide a field from view
@HIDDEN-SURVEY Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Hide in survey mode only
@HIDDEN-FORM Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Hide in data entry form only
@HIDDEN-APP Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Hide in Mobile App only
@HIDDEN-PDF Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Hide from PDF exports
@READONLY Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Make a field non-editable
@READONLY-SURVEY Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Read-only in survey mode only
@READONLY-FORM Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Read-only in data entry form only
@READONLY-APP Visibility RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Read-only in Mobile App only
@RANDOMORDER Radio/Dropdown RC-AT-03 — Radio & Dropdown Action Tags Randomize option display order
@HIDECHOICE Radio/Dropdown RC-AT-03 — Radio & Dropdown Action Tags Hide specific options
@SHOWCHOICE Radio/Dropdown RC-AT-03 — Radio & Dropdown Action Tags Show only specific options
@MAXCHOICE Radio/Dropdown RC-AT-03 — Radio & Dropdown Action Tags Limit selections per option
@NONEOFTHEABOVE Checkbox RC-AT-04 — Checkbox Action Tags Enforce mutually exclusive options
@MAXCHECKED Checkbox RC-AT-04 — Checkbox Action Tags Limit maximum checked boxes
@PASSWORDMASK Free Text RC-AT-05 — Free Text Action Tags Obscure text entry display
@FORCE-MINMAX Free Text RC-AT-05 — Free Text Action Tags Enforce min/max bounds hard
@WORDLIMIT Free Text RC-AT-05 — Free Text Action Tags Cap maximum word count
@CHARLIMIT Free Text RC-AT-05 — Free Text Action Tags Cap maximum character count
@RICHTEXT Free Text RC-AT-05 — Free Text Action Tags Enable formatting in notes box
@PLACEHOLDER Free Text RC-AT-05 — Free Text Action Tags Display hint text in field
@NOW Autofill RC-AT-06 — Autofill Action Tags Fill with current date/time
@NOW-SERVER Autofill RC-AT-06 — Autofill Action Tags Fill with server date/time
@NOW-UTC Autofill RC-AT-06 — Autofill Action Tags Fill with UTC date/time
@TODAY Autofill RC-AT-06 — Autofill Action Tags Fill with current date
@TODAY-SERVER Autofill RC-AT-06 — Autofill Action Tags Fill with server date
@TODAY-UTC Autofill RC-AT-06 — Autofill Action Tags Fill with UTC date
@LONGITUDE Autofill RC-AT-06 — Autofill Action Tags Fill with device longitude
@LATITUDE Autofill RC-AT-06 — Autofill Action Tags Fill with device latitude
@USERNAME Autofill RC-AT-06 — Autofill Action Tags Fill with current username
@CONSENT-VERSION Autofill RC-AT-06 — Autofill Action Tags Fill with e-consent version
@DEFAULT Autofill RC-AT-06 — Autofill Action Tags Pre-fill on first load
@SETVALUE Autofill RC-AT-06 — Autofill Action Tags Pre-fill on every load
@PREFILL Autofill RC-AT-06 — Autofill Action Tags Deprecated alias for @SETVALUE — use @SETVALUE instead
@HIDEBUTTON Cosmetic RC-AT-07 — Cosmetic Action Tags Hide Today/Now button
@INLINE Cosmetic RC-AT-07 — Cosmetic Action Tags Display uploaded file inline
@INLINE-PREVIEW Cosmetic RC-AT-07 — Cosmetic Action Tags Display with toggle button
@IF Conditional RC-AT-08 — Action Tags: @IF — Conditional Logic Apply action tags conditionally based on logic
@CALCTEXT Calculation RC-AT-09 — Action Tags: @CALCTEXT & @CALCDATE — Calculations Calculate text values from expressions
@CALCDATE Calculation RC-AT-09 — Action Tags: @CALCTEXT & @CALCDATE — Calculations Calculate date values from expressions
@LANGUAGE-CURRENT-FORM Language RC-AT-10 — Action Tags: Language Action Tags Capture current language in data entry form
@LANGUAGE-CURRENT-SURVEY Language RC-AT-10 — Action Tags: Language Action Tags Capture current language in survey
@LANGUAGE-SET Language RC-AT-10 — Action Tags: Language Action Tags Switch language based on field value
@LANGUAGE-SET-FORM Language RC-AT-10 — Action Tags: Language Action Tags Switch language in data entry form only
@LANGUAGE-SET-SURVEY Language RC-AT-10 — Action Tags: Language Action Tags Switch language in survey only
@LANGUAGE-FORCE Language RC-AT-10 — Action Tags: Language Action Tags Force page to render in specified language
@LANGUAGE-FORCE-FORM Language RC-AT-10 — Action Tags: Language Action Tags Force language in data entry form only
@LANGUAGE-FORCE-SURVEY Language RC-AT-10 — Action Tags: Language Action Tags Force language in survey only
@LANGUAGE-MENU-STATIC Language RC-AT-10 — Action Tags: Language Action Tags Keep language menu always visible in survey
@APPUSERNAME-APP Mobile App RC-AT-11 — Action Tags: Mobile App Action Tags Fill with mobile app username
@BARCODE-APP Mobile App RC-AT-11 — Action Tags: Mobile App Action Tags Enable barcode/QR code scanning
@HIDESUBMIT External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide all save/submit buttons (HIDESUBMIT module)
@HIDESUBMIT-FORM External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide buttons on data entry forms (HIDESUBMIT module)
@HIDESUBMIT-SURVEY External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide buttons on surveys (HIDESUBMIT module)
@HIDESUBMIT-NEXT External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide Next/Previous buttons (HIDESUBMIT module)
@HIDESAVE External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide save button only (HIDESUBMIT module)
@HIDESAVE-FORM External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide save on forms only (HIDESUBMIT module)
@HIDESAVE-SURVEY External Module RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT Hide save on surveys only (HIDESUBMIT module)

7. Scope of This Series

The Action Tags knowledge base series is organized by tag category:

Article Category Tags Covered
RC-AT-02 — @HIDDEN & @READONLY — Visibility Control Visibility @HIDDEN, @READONLY and all situational variants
RC-AT-03 — Radio & Dropdown Action Tags Radio/Dropdown @RANDOMORDER, @HIDECHOICE, @SHOWCHOICE, @MAXCHOICE
RC-AT-04 — Checkbox Action Tags Checkbox @NONEOFTHEABOVE, @MAXCHECKED
RC-AT-05 — Free Text Action Tags Free Text @PASSWORDMASK, @FORCE-MINMAX, @WORDLIMIT, @CHARLIMIT, @RICHTEXT, @PLACEHOLDER
RC-AT-06 — Autofill Action Tags Autofill @NOW, @TODAY, @LONGITUDE, @LATITUDE, @USERNAME, @CONSENT-VERSION, @DEFAULT, @SETVALUE
RC-AT-07 — Cosmetic Action Tags Cosmetic @HIDEBUTTON, @INLINE, @INLINE-PREVIEW
RC-AT-08 — Action Tags: @IF — Conditional Logic Conditional @IF
RC-AT-09 — Action Tags: @CALCTEXT & @CALCDATE — Calculations Calculation @CALCTEXT, @CALCDATE
RC-AT-10 — Action Tags: Language Action Tags Language @LANGUAGE-* family (9 tags for multi-language projects)
RC-AT-11 — Action Tags: Mobile App Action Tags Mobile App @APPUSERNAME-APP, @BARCODE-APP
RC-AT-EM-01 — External Module Action Tags: HIDESUBMIT External Module @HIDESUBMIT, @HIDESAVE and related variants (HIDESUBMIT module)

8. Common Questions

Q: How do I know if an action tag is available on my REDCap instance?

A: Click any red @ Action Tags button in your project. Only tags available in your current version and module configuration appear in the list.

Q: Can action tags interfere with branching logic?

A: Some can. @HIDDEN overrides branching logic — a field tagged with @HIDDEN is always hidden, regardless of branching logic conditions. See RC-AT-02 — @HIDDEN & @READONLY — Visibility Control for details.

Q: Will adding an unsupported action tag to a field cause an error?

A: Typically no. REDCap silently ignores action tags applied to incompatible field types.