Add a placeholder to list string field (solution)

[Mathilda]

I just wanted to share this solution

if you wish to  add some text like "Select items" to your list string field, you may use this solution

Insert HTML block above the field, disable html editor and insert code:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js">
</script>
<script>
function placeholders() {
document.querySelector("input[type=text][name=ComboBoxInsertRecordField_name]")
.setAttribute("placeholder", "Select items");
}
$(document).ready(placeholders);
</script>

 Replace Field_name with name of your field.