` text itself (as is the case in the following code example), include a [Glyphicon](../components/#glyphicons) (with appropriate alternative text using the `.sr-only` class - see the [Glyphicon examples](../components/#glyphicons-examples)), or by providing an additional [help text](#forms-help-text) block. Specifically for assistive technologies, invalid form controls can also be assigned an `aria-invalid="true"` attribute.
{% endcallout %}
{% example html %}
Input with success
Input with warning
Input with error
{% endexample %}
You can also add optional feedback icons with the addition of `.has-feedback` and the right icon.
{% callout warning %}
#### Icons, labels, and input groups
Manual positioning of feedback icons is required for inputs without a label and for [input groups](../components#input-groups) with an add-on on the right. You are strongly encouraged to provide labels for all inputs for accessibility reasons. If you wish to prevent labels from being displayed, hide them with the `sr-only` class. If you must do without labels, adjust the `top` value of the feedback icon. For input groups, adjust the `right` value to an appropriate pixel value depending on the width of your addon.
{% endcallout %}
{% example html %}
Input with success
(success)
Input with warning
(warning)
Input with error
(error)
{% endexample %}
{% example html %}
{% endexample %}
{% example html %}
{% endexample %}
{% example html %}
{% endexample %}
For form controls with no visible label, add the `.sr-only` class on the label. Bootstrap will automatically adjust the position of the icon once it's been added.
{% example html %}
Hidden label
{% endexample %}
## Control sizing
Set heights using classes like `.input-lg`, and set widths using grid column classes like `.col-lg-*`.
{% example html %}
{% endexample %}
Quickly size labels and form controls within `.form-horizontal` by adding `.form-group-lg` or `.form-group-sm` to existing `.form-group`s.
{% example html %}
{% endexample %}
## Column sizing
Wrap inputs in grid columns, or any custom parent element, to easily enforce desired widths.
{% example html %}
{% endexample %}
## Help text
Block level help text for form controls.
{% example html %}
A block of help text that breaks onto a new line and may extend beyond one line.
{% endexample %}