deprecated

Twig generates a deprecation notice (via a call to the trigger_error() PHP function) where the deprecated tag is used in a template:

{# base.twig #}
{% deprecated 'The "base.twig" template is deprecated, use "layout.twig" instead.' %}
{% extends 'layout.twig' %}

Also you can deprecate a block in the following way:

{% block hey %}
    {% deprecated 'The "hey" block is deprecated, use "greet" instead.' %}
    {{ block('greet') }}
{% endblock %}

{% block greet %}
    Hey you!
{% endblock %}

Note that by default, the deprecation notices are silenced and never displayed nor logged. See Displaying Deprecation Notices to learn how to handle them.