Because the RockRMS check-in app is a window around a web browser that provides label printing connections, there are some things about that web browser that can produce unexpected behavior.

One of those behaviors is that, in many web browsers, the backspace button navigates back one page, just like you're clicking the 'back' button. This is true in Rock check-in as well.  The consequence is that, if a check-in has already occurred, someone pressing the backspace button on a keyboard from the Welcome page can navigate "back" to the page that prints the label tags for the previous guest, resulting in additional labels being printed.

With a quick cut and paste, you can disable that backspace functionality on the Check-in welcome page, preventing this from happening.

First: with an account with appropriate permissions, navgate to Admin Tools > CMS Configuration > Pages.  Select the 'Welcome' page under 'Check-In'

Once you're on the Check-In Welcome page, Edit the page, select 'Advanced Settings' and paste the included code into the "Header Content" field, then save the page settings.

<script>
    
// Prevent the backspace key from navigating back.
$(document).unbind('keydown').bind('keydown', function (event) {
    if (event.keyCode === 8) {
        var doPrevent = true;
        var types = ["text", "password", "file", "search", "email", "number", "date", "color", "datetime", "datetime-local", "month", "range", "search", "tel", "time", "url", "week"];
        var d = $(event.srcElement || event.target);
        var disabled = d.prop("readonly") || d.prop("disabled");
        if (!disabled) {
            if (d[0].isContentEditable) {
                doPrevent = false;
            } else if (d.is("input")) {
                var type = d.attr("type");
                if (type) {
                    type = type.toLowerCase();
                }
                if (types.indexOf(type) > -1) {
                    doPrevent = false;
                }
            } else if (d.is("textarea")) {
                doPrevent = false;
            }
        }
        if (doPrevent) {
            event.preventDefault();
            return false;
        }
    }
});
</script>