Warning Callout
Overview
- Adds a cautionary callout box to the top of the form
- Draws attention to an irreversible or important action
- Helps prevent mistakes before a form is submitted
- Sits above the fields without changing any of them
- Applied as form-configuration JSON in the header, so it changes nothing about the data
- Works on any list form, and the message is easy to edit
Common Use Cases
- Approval or sign-off forms
- Forms that trigger a workflow
- Financial or purchase requests
- Deletion or cancellation forms
- Compliance attestations
- Any form with a high-stakes action
Details
- Design Pattern: Form Design
- Format Scope: Form
How to Apply JSON code
- Open the list, then open any item to show its form.
- At the top of the form, expand the Edit form (pencil) icon and choose Configure layout.
- In the Apply formatting to dropdown, choose Header.
- Paste the JSON below into the box, preview, and click Save.
JSON Code
{
"elmType": "div",
"style": {
"display": "flex",
"align-items": "flex-start",
"width": "100%",
"box-sizing": "border-box",
"background-color": "#fff4ce",
"border-left": "4px solid #c19c00",
"border-radius": "6px",
"padding": "12px 14px",
"margin-bottom": "14px"
},
"children": [
{
"elmType": "span",
"attributes": {
"iconName": "Warning"
},
"style": {
"font-size": "16px",
"color": "#8a6d00",
"margin-right": "10px",
"flex-shrink": "0"
}
},
{
"elmType": "div",
"style": {
"font-size": "13px",
"color": "#5c4a00",
"line-height": "1.5",
"font-weight": "600"
},
"txtContent": "Submitting this form starts an approval that cannot be undone. Double-check the amount and the approver before you save."
}
]
}Common Questions About the Warning Callout
What is the Warning Callout built with?
It is built with a standard Microsoft List (SharePoint list) and form-configuration JSON applied to the form header. There is no custom development, no SPFx solution, and no third-party tools. It is the kind of clean, maintainable formatting Greg Zelfond builds for teams that want clearer forms without ongoing development overhead.
Can the warning change based on the item?
Yes. The callout can always show, or it can be set to appear only when a field meets a condition – for example a large amount or a specific category. The wording and any condition are set in the JSON.
Does this design use any custom development or third-party tools?
No. It uses only out-of-the-box SharePoint form configuration, which Microsoft supports natively. That keeps it stable and easy to maintain, and nothing breaks when SharePoint is updated. Out-of-the-box is the only way Greg builds, so you can own and extend the design yourself for years.
If LookBook 365 is code-free and out-of-the-box, why does this example include JSON?
Because SharePoint formatting JSON is not custom code – it is a native configuration feature built into lists and libraries. It is declarative: it only describes how an existing form looks, and cannot run scripts, reach external services, or change your data. Nothing is deployed and nothing breaks when Microsoft updates SharePoint, and you can edit or remove it anytime. That is why LookBook 365 treats it as out-of-the-box and low risk.
Does it stop people from submitting?
No – it draws attention but does not block the form. It is a visual caution. If you need to actually prevent submission, that is handled by field validation, which Greg can set up alongside the callout.
Can Greg build form formatting like this for our team?
Yes – this is exactly the kind of work Greg Zelfond does. As an independent SharePoint consultant and Microsoft MVP, he designs out-of-the-box list and library form formatting like this so your team can read and maintain it without a developer. Reach out through the contact page to talk about your forms.
