Hi Bharamani,
Got it: you're referring to the id in the HTML produced by Orbeon Forms. In that id, you can change the "section-1" and "control-2" parts, as they are derived respectively from your section and control name. But you have no control over the rest of the id, so better not rely on it in your own CSS or JavaScript.
And of course, just let us know if because of this there is something you're having hard time doing.
Alex
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