Question - form_remote_for vs remote_form_for

I need to use remote_form _for

<% form_for :canskill, :url => canskill_url, :candidate_id =>
@candidate_id
do |form| %>

However I’m not sure and can’t find where I put the :html => { :id =>
‘…-form’ } do |f| ?

Anyone know ?
TIA
Stuart