what is attr 'gtbfieldid' and how to avoid autocomplete behavior?

I have this simple form:

class PagoDesde(forms.Form):
    from django import forms as f
    desde = f.DateField(input_formats=['%d/%m/%Y'])

In my template:

    {{ form.desde }}

And has associated a jqueryui.datepicker in the document.ready

    $("#id_desde").datepicker();

The html result is:

<input type="text" id="id_desde" name="desde" 
class="hasDatepicker" gtbfieldid="598"/>

And it works great, but I have

2 questions:

• what is gtbfieldid="598"? does jquery add that?
• how to avoid the autocomplete behavior of the browsers in this textfield?

thanks :)