Q:

Twig and autoescaping

I'm learning Symfony2.  Currently, I'm trying to render a form label in a twig template.  The label includes an html tag, that is not rendered correctly in my twig file. 
Here follows the piece of code where the form field is created:
$builder->add('zipcode', 'integer', array(
        'label' => '<abbr title="Zone Improvement Plan">CAP</abbr> code',
        ));

In the twig file I render the field label as follows:
{{ form_label(form.zipcode) }}

I tried the raw, escape, e filters, but the results provided in my html page is always the string
 <abbr title="Zone Improvement Plan">CAP</abbr> code

and not the corresponding HTML code! 
Any suggestion? 
Thanks in advance! 
Later I found the solution.  
The solution is to disable the autoescape within the label block provided by Symfony at path: 
     symfony / src / Symfony / Bridge / Twig / Resources / views / Form / form_div_layout.html.twig 
So, in your twig file you have to put the following lines outside the form:
    {% form_theme form _self %}
{% block generic_label %}
{% spaceless %}
  {% if required %}
      {% set attr = attr|merge({'class': attr.class|default('') ~ ' required'}) %}
  {% endif %}
  <label{% for attrname,attrvalue in attr %} {{attrname}}="{{attrvalue}}"{% endfor %}>{% autoescape false %}{{ label|trans }}{% endautoescape %}</label>
{% endspaceless %}
{% endblock %}

A:

From JeanValjean himself :
{% autoescape false %}{{ form.zipcode.vars.label | trans }}{% endautoescape %}

And to generalize this behaviour to your whole app, you can override the form block for labels  :
{% block generic_label %}
    {% spaceless %}
        {% if required %}
            {% set attr = attr|merge({'class': attr.class|default('') ~ ' required'}) %}
        {% endif %}
        <label{% for attrname,attrvalue in attr %} {{attrname}}="{{attrvalue}}"{% endfor %}>
            {% autoescape false %}{{ label|trans }}{% endautoescape %}
        </label>
    {% endspaceless %}
{% endblock %}

A:

To disable the autoespace filter just to render a variable is not the best thing because when you read the code it's not really clear. 
So, instead of :
{% autoescape false %}{{ label|trans }}{% endautoescape %}

You can use :
{{ label|trans|raw }}

