" The Content Optimization System matches content with context to create a highly personalized, relevant and meaningful customer experience. "
To add an editor placeholder to a custom module, first add an [if statement](/cms/reference/hubl/if-statements) to the module's HTML to render the placeholder when there's no content selected in the editor. For example, the following code could be used to add an editor placeholder to a CTA module:
```jinja theme={null}
{% if module.label %}
{% cta guid="{{ module.guid }}" label="my_cta" %}
{% elif is_in_editor %}
{% editor_placeholder %}
{% endif %}
```
```
```
```
