Intercept TextFrame deletion through a script

How about attaching an event to the menuAction?

#targetengine "session"
if (app.menus.itemByName("Main").submenus.itemByName("$ID/Edit").menuItems.itemByName("$ID/Clear").associatedMenuAction.eventListeners.itemByName("beforeInvokeClear").isValid) {
    app.menus.itemByName("Main").submenus.itemByName("$ID/Edit").menuItems.itemByName("$ID/Clear").associatedMenuAction.eventListeners.itemByName("beforeInvokeClear").remove();
}
app.menus.itemByName("Main").submenus.itemByName("$ID/Edit").menuItems.itemByName("$ID/Clear").associatedMenuAction.addEventListener(
    MenuAction.BEFORE_INVOKE, function(myEvent) {
        for (var i = 0; app.activeDocument.selection.length > i ; i++) {
            if (app.activeDocument.selection[i] instanceof TextFrame) {
                alert("Please do not delete the text frame.");
                myEvent.preventDefault();
                break;
            }
        }
    }).name = "beforeInvokeClear";

Are you talking about an event - the moment user hits Delete key - or checking during next opening of the file for missing objects ? 

Hi @lo22764185qzp2 ,

there is nothing you can do if you make the document available to someone else who is not working on your machine with your version of InDesign.

Theoretically one  could install a startup script with an event handling mechanism that can detect the document and a list of text frames identified by their IDs. But a clever user can work around this by exporting the document to IDML and open the IDML file as new document…

What you can do is lock items like text frames.

Text is still editable if InDesign's preferences are set to allow the selection of locked items.

But this is not a document specific preference:

Preferences > General > Object Editing

[  ] Prevent Selection of Locked Objects

Regards,
Uwe Laubender
( Adobe Community Expert )