Intel/Siemens/ISEF question

<p>I wasn't sure where to post this, but I was wondering if there is a maximum number of times that you can enter a project into various science competitions, notably Intel, Siemens, ISEF...</p>

<p>For example, I believe that for Intel, you can only submit one project, ever (over all 4 years in HS). I believe for ISEF, you can submit a different project during different years, but only one entry per year. And Idk about Siemens.</p>

<p>Can anyone with knowledge of these elite science comps shed some light on this? Thx.</p>